Small Takes of Marine Mammals Incidental to Specified Activities; Explosives Testing at Eglin Air Force Base, FL

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 092498A]

Small Takes of Marine Mammals Incidental to Specified Activities;

Explosives Testing at Eglin Air Force Base, FL

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and

Atmospheric Administration (NOAA), Commerce.

ACTION: Notice of receipt of application and proposed authorization for

a small take exemption; request for comments.

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SUMMARY: NMFS has received a request from the U.S. Air Force to take,

by harassment and non-serious injury, bottlenose dolphins, spotted

dolphin, and possibly other cetacean species incidental to explosive

testing of obstacle and mine clearance systems at Eglin Air Force Base

(Eglin). Under the Marine Mammal Protection Act (MMPA), NMFS is

requesting comments on its proposal to authorize these takings for a

period not to exceed 1 year.

DATES: Comments and information must be received no later than November

12, 1998.

ADDRESSES: Comments on this application should be addressed to Michael

Payne, Chief, Marine Mammal Division, Office of Protected Resources,

NMFS, 1315 East-West Highway, Silver Spring, MD 20910. A copy of the

application and draft environmental assessments (EAs) may be obtained

by writing to this address or by telephoning the contact listed here.

FOR FURTHER INFORMATION CONTACT: Kenneth Hollingshead 301-713-2055, or

David Bernhart, 727-570-5312.

SUPPLEMENTARY INFORMATION:

Background

Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1361 et seq.) directs

the Secretary of Commerce to allow, upon request, the incidental, but

not intentional, taking 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

regulations are issued.

Permission may 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 subsistence uses and that the permissible methods of

taking and requirements pertaining to the monitoring and reporting of

such taking are set forth. NMFS has defined ``negligible impact'' in 50

CFR 216.103 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.''

Subsection 101(a)(5)(D) of the MMPA established an expedited

process by which U.S. citizens can apply for an authorization to

incidentally take small numbers of marine mammals by harassment for a

period of up to 1 year. The MMPA defines ``harassment'' as:

any act of pursuit, torment, or annoyance which (a) has the

potential to injure a marine mammal or marine mammal stock in the

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wild; or (b) has the potential to disturb a marine mammal or marine

mammal stock in the wild by causing disruption of behavioral

patterns, including, but not limited to, migration, breathing,

nursing, breeding, feeding, or sheltering.

Subsection 101(a)(5)(D) establishes a 45-day time limit for NMFS

review of an application followed by a 30-day public notice and a

comment period on any proposed authorizations for the incidental

harassment of small numbers of marine mammals. Within 45 days of the

close of the comment period, NMFS must either issue or deny issuance of

the authorization.

Summary of Request

On July 20, 1998, NMFS received a complete application from the Air

Force Development Test Center, Department of the Air Force, Eglin. The

Air Force, in cooperation with the Naval Surface Warfare Center-Coastal

Systems Station (NSWC-CSS), U.S. Navy, is requesting an authorization

to take, by harassment and non-serious injury, bottlenose dolphins

(Tursiops truncatus), spotted dolphins (Stenella plagiodon), and

possibly other cetacean species incidental to explosive testing of

obstacle and mine clearance systems at Eglin. Eglin is located in the

Florida Panhandle approximately midway between the cities of Pensacola

and Panama City, FL. The location of the proposed action is on the

beach areas on Santa Rosa Island (SRI), approximately 27 kilometers

(km)(17 miles (mi)) west of Destin, FL.

The Navy's current capability to clear obstacles and mines in the

surf zone is limited to the hand placement of explosive charges by Navy

combat swimmers. The effectiveness of this capability is limited by the

ability of swimmers to locate submerged targets and to carry sufficient

explosives to destroy the targets. Such operations are considered

highly hazardous, and the reliability of obstacle removal is considered

to be poor. To facilitate U.S. Marine amphibious assaults, the U.S.

Navy is committed to developing and testing methods to safely and

effectively clear a path through such obstacles.

NWSC-CSS has requested permission from Eglin to test four anti-mine

systems in the shallow surf zone along U.S. Air Force-controlled lands

of SRI. The four test systems are the Shallow Water Assault Breaching

(SABRE) system, the Distributed Explosive Technology (DET) system, the

MK-82 general purpose bombs (GPBs), and the MK-5 Mine Clearance System

(MCS).

The proposed action is to perform up to a total of 10 underwater

detonation tests (2 tests using the SABRE system and up to 8 tests

using the DET array); and a series of tests of explosive systems at

Eglin.

In order to avoid impacting the endangered West Indian manatee

(Trichiechus manatus)(which is more commonly found south of the region

and during warmer months) and sea turtles, tests will be conducted in

the fall and winter 1998/99. While a brief description of the four

systems proposed for testing are described here, more detailed

descriptions of the activity and the expected impact can be found in

the application and in the two EAs on the activities. These documents

are available upon request (see ADDRESSES).

SABRE System

An operational full-length SABRE-line charge consists of 130 10-

pound (lb)(4.5 kg) net explosive weight (N.E.W.) charges on 3-ft (0.9

m) centers which is deployed from a Landing Craft Air-Cushion (LCAC) by

an MK-22 Mod 4 rocket motor. Each charge consists of approximately 9.6

lb (4.3 kg) of PBXN-103 explosive and a W-11 booster, weighing

approximately 0.4 lb (0.2 kg). A detonating cord runs through the

centers of the booster and main charge.

For the two proposed tests, a total of 22 and 23 SABRE charges will

be hand-laid on the sea bottom, perpendicular to the beach in 3 ft (.91

m) and 10 ft (3.0 m) of water, respectively. For both tests, the

detonation sequence will be from the offshore end toward the beach. For

these events, 27 to 31 inert mines will be placed perpendicular to the

line charge and parallel to the shoreline. Total NE.W. of the SABRE

tests will be 221 lbs (100.2 kg) and 232 lbs (105.2 kg), respectively.

DET System

An operational, full-size DET array consists of parallel lines of

detonating cord, whose overall footprint is 180 by 180 ft (54.9 m by

54.9 m). The array is packed in a container and launched from an LCAC

by two MK-22 Mod 4 rocket motors for expansion and subsequent

deployment.

Full-scale systems are not required for these tests. Previous tests

have shown that partial-length SABRE segments and partial-size DET

arrays are adequate for evaluations. The data acquired from small-scale

tests can be scaled up in order to make predictions for military

applications. Thus, for the DET system, the Navy is proposing to use an

11-ft by 60-ft (3.3 m by 18.3 m) DET array in 3 ft (0.9 m) of water.

There will be eight separate DET events, spanning several days, with

two to three arrays tested per day. The NE.W. of each array is 42 lbs

(19 kg), with arrays being detonated at the seaward end. Each array

will be placed above a maximum of four live mines consisting of either

22 or 26.4 lbs (10 or 12 kg) of explosive. Depending upon the mine

type, total NE.W. of each test therefore would be up to either 130 lbs

(59 kg) or 147.6 lbs (67 kg). DET events will be hand-deployed from a

boat and exploded electronically by trained personnel.

MK-82 GPBs

The proposed action is an evaluation of the MK-82 GPBs to clear

anti-invasion beach obstacles and mines in the surf zone. The MK-82

GPBs to be tested consist of seven GPBs, each containing 192 lbs (87.1

kg) of explosive for a total NE.W. of 1,344 lbs (610 kg). The

configuration for testing will be a linear arrangement of seven bombs

spaced 24 ft (7.3 m) apart, located parallel to the shoreline in 6 ft

(1.8 m) of water.

Two separate deployments and firings are required to test this

configuration. All MK-82s will be buried vertically to approximately

one-half length (about 3 ft (0.9 m) by jetting. The MK-82s will be

detonated using approximately 1/4 block of C-4 explosive paced into the

aft fuse well. The MK-82s will be detonated simultaneously in 6 ft (1.8

m) of water using remote detonators to detonate the C-4. Beach

obstacles (log posts, concrete cubes, and steel hedgehogs) and inert

mines will be placed around the bombs to serve as targets for bomb

fragments and blast.

MK-5 MCS

The MK-5 MCS consists of a 350-ft (106.7 m) continuous length

charge of composition C-4 explosive (with a distribution of 5 lb (2.3

kg) per linear foot and a pair of detonating cords (totaling 11 lbs (5

kg). Total NE.W. of the system is 1,750 lbs (794 kg). The MK-5 MCS

would be deployed in the surf zone about 550 ft (167.6 m) from shore by

an LCAC. Once fully deployed, it will then be detonated. Testing will

take place over a 3-day period. On the first day, there will be inert

firings of four MK5 systems. The second day will consist of one inert

firing and one live firing of a MK5 system. The third day will consist

of three separate live firings.

Description of Habitat and Marine Mammals Affected by the Activity

A description of the project area ecosystem in the eastern Gulf of

Mexico (GOM) can be found in the application and in the associated

draft EAs and need not be repeated here.

[[Page 54678]]

Marine Mammals

Although approximately 27 species of marine mammals (whales,

dolphins and porpoises) reside in or pass through the northeastern GOM,

the only species of marine mammals that are likely to be impacted by

the activities proposed for the shallow coastal waters off SRI are the

bottlenose dolphin (Tursiops truncatus) and the Atlantic spotted

dolphin (Stenella frontalis). Information on these two species may be

found in the application and in the supporting EAs for these projects.

Additional information on these and other species of marine mammals in

the GOM can be found in Blaylock et al. (1995) and Waring et al.

(1997). Please refer to those documents for information on the biology,

distribution, and abundance of these species.

Potential Effects of Explosives on Marine Mammals

Potential impacts to those marine mammal species known to occur in

the SRI area from explosives include both lethal and non-lethal injury,

as well as incidental harassment. The pressure wave from the explosive

can impact air cavities, such as lungs and intestines. Extensive

hemorrhaging into the lungs due to underwater shock waves may cause

death to a marine mammal through suffocation (Hill, 1978). Other common

injuries which may result in mortality include circulatory failure,

broncho-pneumonia in damaged lungs, or peritonitis resulting from

perforations of the intestinal wall (Hill, 1978). Because impulse

levels sufficient to cause lethal injury increase with increased mammal

mass (Yelverton et al., 1973), conservative criteria are based on the

lowest possible affected mammalian weight (e.g., an infant dolphin).

Extensive lung hemorrhage is an injury which would be debilitating, and

not all animals would be expected to survive (1 percent mortality is

predicted at the onset level). As the severity of extensive lung

hemorrhage increases beyond the onset level, gastro-intestinal tract

injuries can increase significantly. The expected mortality level

associated with these combined severe injuries would be significantly

higher than 1 percent (U.S. Navy, 1998).

Non-lethal injuries involve slight lung hemorrhage and tympanic

membrane (TM) rupture from which the mammal is expected to recover

(Yelverton et al., 1973; Richmond et al., 1973). Eardrum damage

criteria are based upon a limited number of small charge tests

(Yelverton et al., 1973; Richmond et al., 1973). Ranges for percent TM

rupture incurred by underwater explosives can be calculated by a

conservative TM damage model (U.S. Navy, 1996). General criteria for TM

damage has been reported to occur at impulse levels down to 20 psi-msec

(Yelverton et al., 1973).

Because eardrum (e.g., TM) rupture, rather than slight lung

hemorrhage, usually occurs at lower impulse levels, TM rupture is used

by NMFS and others to conservatively define the non-lethal injury zone.

A maximum impulse of 10 psi-msec is often considered to define the non-

lethal injury zone, where a very low incidence of blast injuries are

likely to occur (Yelverton et al., 1973). A level of pressure impulse

at which marine mammals are not expected to experience non-lethal

injury (nor instantaneous mortality or lethal injury) is reported to be

5 psi-msec (Yelverton et al., 1973). This is the impulse level adopted

by the Air Force to designate no injurious takings by this activity.

In addition to lethal, serious, and non-serious injury, harassment

of marine mammals may occur as a result of non-injurious physiological

responses to an explosion-generated shockwave and its acoustic

signature. Based upon information provided in the SEAWOLF shock trial

final environmental impact statement (U.S. Navy, 1998), a dual

criterion for marine mammal acoustic harassment has been developed for

explosive-generated signals: (1) an energy-based temporary threshold

shift(TTS) injury criterion of 182 dB re 1 uPa2 -sec derived

from experiments with bottlenose dolphins (Ridgway et al., 1997), and

(2) a 12 lbs/in2 (psi) peak pressure cited by Ketten (1995)

as associated with a ``safe outer limit (for the 10,000 lb charge for

minimal, recoverable auditory trauma'' (i.e., TTS)). For this activity,

noise levels that fall between the 5 psi-msec and out to a transmission

distance where a noise level of 180 dB re 1 uPa2 -sec (Air

Force, 1998) will be considered to fall within the incidental

harassment zone.

The potential impact to Atlantic bottlenose dolphins and the

Atlantic spotted dolphins, the two species that may potentially be

affected, was evaluated using modeling on the effects of underwater

explosions resulting from each of the test systems described previously

(see application). Based upon data provided in Tables 5.2 and 5.3 in

the application, the maximum number of Atlantic bottlenose dolphins

potentially injured from all tests ranges from 4 to 13. The maximum

number of Atlantic spotted dolphins potentially injured from all tests

combined is less than 1. These are the maximum injury levels without

implementation of mitigation.

The estimated total numbers of bottlenose dolphins and spotted

dolphins potentially exposed to takes by harassment are 33 and 1,

respectively. The total number of bottlenose dolphins potentially

exposed to noise from the source of the noise to 180 dB re 1

uPa2 -sec ranges from 4 to 15 for the MK-82 GPB tests, 1 to

3 for the MK5 MCS tests, 1 to 2 for the combined SABRE tests, and 4 to

13 for all DET array tests combined. However, mitigation is expected to

obviate any injury to marine mammals.

Mitigation

There are two forms of mitigation: (1) natural, as provided by the

environment and (2) human, designed to protect marine mammals to the

greatest extent practicable.

Natural mitigation: Physical characteristics of the proposed test

area and test methods will ameliorate the underwater shock wave. Tests

will be conducted in approximately 3 to 10 ft (0.9 to 3.0 m) of water.

At this shallow depth, some protection of the energy from the

detonations will be directed through the surface of the water rather

than transmitted through the water. Another consequence of the shallow,

as opposed to the deep water detonation depth is that bubble pulse is

not significant and there will be far less energy in any oscillations.

Additionally, these tests will be conducted inside the offshore bar at

the SRI site. The offshore bar ameliorates the transmission of the

underwater portion of the shock wave. Also, MK-82 GPBs will be buried

in bottom sands to approximately their center of gravity (3 ft (0.9 m),

a factor expected to mitigate the transmission of the shock wave as the

detonations will be directed downwards.

Human mitigation: Eglin has established safety zones to prevent

marine mammal injury for each test. These safety zones are: 0.75 km for

SABRE-22, 1.0 km for SABRE-23, 1.0 km for DET, 6.0 km for MK-82 GPB,

and 0.5 km for MK-5 MCS.

Eglin has proposed that base personnel conduct a 30-minute pre-

detonation aerial monitoring survey immediately prior to each test to

ensure no marine mammals are within each test area's designated safety

zone. With water depths less than 18 m (59 ft), low turbidity, and

white sand bottom, exceptional marine mammal visibility is ensured.

Aerial surveys will be conducted at approximately 100 ft (30.5 m)

elevation.

In order to ensure adequate visibility for locating marine mammals

(and sea turtles), no tests will take place if sea state conditions are

greater than

[[Page 54679]]

category 3 and water clarity is not adequate for conducting surveys. No

tests will take place if marine mammals or sea turtles are sighted

within the safety zone.

Monitoring

In addition to pre-detonation monitoring mentioned previously,

Eglin will conduct aerial surveys immediately following each detonation

event. The post-test monitoring will be conducted in a similar manner

to the pre-test monitoring, except that observation personnel will be

focused on locating any injured marine mammals. If any injured marine

mammals are observed during post-test monitoring, subsequent

detonations will be postponed, and the local stranding network

notified. The project will be required to be reviewed by Air Force and

NMFS personnel prior to conducting any additional tests.

Reporting

Any takes of marine mammals other than authorized by the Incidental

Harassment Authorization (IHA) will be reported to the Regional

Administrator, NMFS, by the next working day. A draft final report of

the entire test results and marine mammal observations for pre- and

post-detonation monitoring will be submitted to NMFS within 90 days

after completion of the last test. Unless notified by NMFS to the

contrary, that draft final report will be considered the final report

under the IHA.

National Environmental Policy Act (NEPA)

As part of its request for a small take authorization, the U.S. Air

Force has prepared two EAs, one for SABRE and DET and a second document

for the MK-82/MK-5 systems. These EAs, which supplement information

contained in the application, are necessary for determining whether the

activities proposed for receiving small take authorizations are having

a negligible impact on affected marine mammal stocks. The U.S. Air

Force is accepting comment on these EAs, and, based upon the comments

received on this proposed authorization, NMFS will (1) adopt the U.S.

Air Force EAs as its own and sign a Finding of No Significant Impact

(FONSI) statement, (2) amend the U.S. Air Force EA to incorporate

relevant comments, suggestions, and information and to sign a new FONSI

statement, or (3) based upon comments received, prepare and release for

comment a Draft EA.

Consultation

Under section 7 of the Endangered Species Act, NMFS has begun

consultation on the proposed issuance of an incidental harassment

authorization. Consultation will be concluded upon completion of the

comment period after taking into consideration the comments received on

the proposed issuance of an IHA.

Proposed Authorization

NMFS proposes to issue an IHA to the U.S. Air Force for the

incidental harassment and non-serious injury of a small number of

bottlenose dolphins, spotted dolphins, and possibly other cetacean

species. NMFS has preliminarily determined that, provided the proposed

mitigation measures are enacted, the short-term impact of explosives

testing for obstacle and mine clearance systems at Eglin has the

potential to result in no more than a negligible impact on affected

marine mammal stocks.

Information Solicited

NMFS requests interested persons to submit comments, information,

and suggestions concerning this request (see ADDRESSES).

Dated: October 6, 1998.

Hilda Diaz-Soltero,

Director, Office of Protected Resources, National Marine Fisheries

Service.

[FR Doc. 98-27393 Filed 10-9-98; 8:45 am]

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