Navy Seeks Permit to Use Sonar During RIMPAC Exercises

WASHINGTON, DC, April 26, 2006 (ENS) - NOAA Fisheries Service is seeking public comments on the U.S. Navy's proposal to conduct Rim of the Pacific (RIMPAC) anti-submarine arfare exercises around the Main Hawaiian Islands using tactical mid-frequency sonar.

The mid-frequency sound generated by the tactical sonar used in the exercises has the potential to disrupt the behavior of individual marine mammals in close proximity to the exercises. Up to 22 species of marine mammals inhabit this area of the Pacific. The Navy is requesting an authorization under the Marine Mammal Protection Act.

RIMPAC is a multi-national training exercise that has been conducted every other year since 1968. This year, RIMPAC is scheduled to occur June 26 through July 28, with exercises using sonar planned on 21 days.

In their application for an Incidental Harassment Authorization, the Navy proposed several standard protective measures to be implemented during the RIMPAC exercises. NOAA Fisheries Service has worked closely with the Navy to develop a suite of additional mitigation and monitoring measures designed to reduce the likelihood of harassment. These additional measures would be required during RIMPAC.

"Our scientists believe these measures, if fully implemented, will avoid the potential for serious injury or mortality to marine mammals," said Dr. Bill Hogarth, NOAA Fisheries Service director. "These mitigation measures will significantly reduce the number of marine mammals exposed to levels of sound likely to cause a behavioral disruption. These safeguards are a result of the high level of cooperation that we have had with the Navy."

During the RIMPAC exercises, the Navy will implement safety zones around all vessels using active sonar, and will reduce power or shut down sonar operations if marine mammals are seen within the zones.

At night or low visibility times, the Navy will use infrared or passive acoustics.

If marine mammals cannot be fully detected out to the prescribed safety zone, sonar will be powered down as if a marine mammal were present immediately beyond their visual range.

During the RIMPAC exercises, with the exception of three closely monitored choke-point exercises, mid-frequency sonar will not be operated in canyon-like areas, in constricted channels, or within certain distances around the islands.

Choke-point exercises involve vessels moving through constricted channels, sweeping the area with sonar, similar to operational situations where they would anticipate submarine ambushes.

During the choke-point exercises, the Navy will use additional dedicated shipboard marine mammal observers; use additional dedicated aerial and vessel-bound observers, and land-based observers; and contract with experienced cetacean researchers to monitor the behavior of marine mammals in the vicinity of the exercises.

NOAA Fisheries Service will accept comments on the application and proposed authorization through May 24. Comments should be addressed to: Steve Leathery, Chief of the Permits, Conservation, and Education Division; Office of Protected Resources, NMFS; 1315 East West Highway, Silver Spring, MD 20910.

Comments may be sent by e-mail to PR1.011806L@noaa.gov. A copy of the application and federal register notice may be obtained by contacting the same office.