Navy eyes sonar operations in Marianas

Navy eyes sonar operations in Marianas

Thursday, October 22, 2009

NOAA's Fisheries Service is seeking comments now through Nov. 19 on its proposed rule to authorize impacts to marine mammals during Navy training exercises around the Mariana Islands. The NOAA proposal includes protective measures designed to minimize effects on marine mammals.

The Navy has requested an authorization under the Marine Mammal Protection Act, because the mid-frequency sound generated by tactical sonar, and the sound and pressure generated by detonating explosives, may affect the behavior of some marine mammals, or cause a temporary loss of their hearing sensitivity.

NOAA's Fisheries Service does not expect the exercises to result in serious injury or death to marine mammals, and is proposing the Navy use mitigation measures to avoid injury or death. However, exposure to sonar in certain circumstances has been associated with the stranding of some marine mammals, and some injury or death may still occur. Therefore, the proposed authorization allows for a small number of incidental injuries to marine mammals.

NOAA's Fisheries Service said it has made a preliminary determination that these effects “would have a negligible effect” on the species or stocks involved.

Under the authorization, the Navy would have to follow mitigation measures to minimize effects on marine mammals, including:

-establishing marine mammal safety zones around each vessel using sonar;

-using Navy observers to shut down sonar operations if marine mammals are seen within designated safety zones;

-using exclusion zones to ensure that explosives are not detonated when animals are detected within a certain distance;

-implementing a stranding response plan that includes a training shutdown provision in certain circumstances, and allows for the Navy to contribute in-kind services to NOAA's Fisheries Service if the agency has to conduct a stranding response and investigation.

“These measures should minimize the potential for injury or death, and significantly reduce the number of marine mammals exposed to levels of sound likely to cause temporary loss of hearing,” NOAA said in a statement.

Additionally, the proposed rule would require the Navy and NOAA's Fisheries Service to meet yearly to discuss new science, Navy research and development, and Navy monitoring results to see if changes to mitigation or monitoring measures are needed.

NOAA's Fisheries Service and the Navy use independent, experienced vessel-based marine mammal observers (as well as Navy watchstanders), and passive acoustic monitoring to help better understand how marine mammals respond to various levels of sound and to assess the effectiveness of mitigation measures.

The Navy has been conducting training exercises, including the use of mid-frequency sonar, in the Mariana Islands for more than 60 years. Exercises range from large, 10-day long joint multi-strike group exercises using multiple surface vessels, submarines and aircraft, to multi-hour exercises designed to target specific skills or weapons systems, such as missile tracking. Some exercises involve explosives.

NOAA's Fisheries Service will accept comments on the application and proposed authorization through November 19. Comments should be addressed to:

Michael Payne, Chief of the Permits, Conservation, and Education Division
Office of Protected Resources, NMFS
1315 East West Highway
Silver Spring, MD 20910

Electronic public comments may be submitted via the Federal eRulemaking Portal http://www.regulations.gov using the identifier 0648-AW91. (NOAA)