Notice of Intent To Prepare an Environmental Impact Statement for Continued Operation of the Sound Source Installed by the Acoustic Thermometry of Ocean Climate (ATOC) Project North of Kauai

DEPARTMENT OF DEFENSE

Department of the Navy, Office of Naval Research

Notice of Intent To Prepare an Environmental Impact Statement for

Continued Operation of the Sound Source Installed by the Acoustic

Thermometry of Ocean Climate (ATOC) Project North of Kauai

SUMMARY: Pursuant to section 102(2)(c) of the National Environmental

Policy Act (NEPA), the Office of Naval Research (ONR) is announcing its

intent to prepare an Environmental Impact Statement (EIS) to continue

operation of the sound source installed by the ATOC Project north of

Kauai.

DATES: Public scoping meetings will be held in: (1) Hanalei, Kauai on

June 29, 1999 at 7 PM at the Wai'oli Hui'ia Church, Mission Hall, 5-

5363 Kuhio Highway; (2) Lihue, Kauai on June 30, 1999 at 7 PM at the

Kauai Community College Dining Room, 3-1901 Kaumualii Highway; and (3)

Honolulu, Hawaii on July 1, 1999 at 7 PM at the Hawaii Imin Intl.

Conference Center, East-West Center, 2nd Floor, Pacific Room, 1777

East-West Road. Written comments regarding the scope of this

environmental document must be submitted by 08/15/99.

ADDRESSES: Comments and requests for additional information should be

addressed to ATTN: Office of Naval Research, c/o Kathleen J. Vigness,

(703) 465-8404, Marine Acoustics, Inc., 901 N. Stuart St., Suite 708,

Arlington, VA 22203.

SUPPLEMENTARY INFORMATION: The Kauai ATOC Feasibility Study began in

October 1997, and included a Marine Mammal Research Program (MMRP) for

which a Scientific Research Permit was obtained. The sound source

installed by the ATOC Project is located approximately 14.7 km (8 nm)

north of Kauai at 22 deg. 20.94 N, 159 deg. 34.18 W at a depth of 807 m

(2648 ft). During the ATOC Project, a team of marine mammal researchers

utilized transmissions of the sound source to conduct simultaneous

observations of marine mammal behavior. The acoustic objectives of the

ATOC Feasibility Study were to determine the precision with which

acoustic methods could be used to measure large-scale changes in ocean

temperature and heat content, thereby refining climate models and

gaining a better understanding of the potential for global warming. The

objectives of the MMRP were to determine the potential effects of the

sound source on marine animals.

The results of the ATOC Project demonstrate that acoustic travel

times can be measured much more accurately than expected. These travel

times can then be used to estimate range- and depth-averaged

temperatures with a precision of about 0.006 deg.C at ranges of 3,000

to 5,000 km. The marine mammal research indicates that transmissions by

the sound source do not affect the abundance, distribution or singing

behavior of humpback whales in the vicinity of the sound source, and

that there were no biologically significant short-term effects observed

in conjunction with the transmissions. The MMRP found that the distance

and time between successive whale surfacings increased slightly with

increasing sound levels.

With these positive results, the Office of Naval Research will

prepare an EIS to continue operation of the sound source installed by

the ATOC Project. The sound source would remain at its present

location, and transmissions would continue with the same signal

parameters and approximately the same transmission schedule. The

current schedule maintains six 20-minute transmissions (one every four

hours), every fourth day, with each transmission preceded by a 5-minute

ramp-up period, representing an average duty cycle of 2%. With the

possible exception of equipment failures or short duration testing,

this schedule would continue for a period of five years. The signals

transmitted by the source have a center frequency of 75 Hz and a

bandwidth of approximately 35 Hz (i.e., sound transmissions are in the

frequency band of 57.5-92.5 Hz). Approximately 260 watts of acoustic

power are radiated during transmission. At 1 m (3.28 ft) from the

source, the sound intensity is about 195 dB referenced to the intensity

of a signal with a sound pressure level of 1 microPascal (on a ``water

standard'' basis). These signal parameters and source level have been

found to provide adequate, but not excessive, signal-to-noise ratios at

the receiver ranges of interest.

The EIS will address the potential effects of the transmissions on

the marine environment, including potential auditory, behavioral, and

physiological effects on marine mammals and other marine creatures.

Alternatives will be studied, including the no action alternative.

Dated: June 8, 1999.

Jeffrey Simmen,

Ocean Acoustics Program, Office of Naval Research.

[FR Doc. 99-15157 Filed 6-14-99; 8:45 am]

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