NOAA Seeks Comments on Proposed Authorization for Navy Sonar Operations off the Coast of the Mariana Islands

October 20, 2009

NOAA’s Fisheries Service is seeking comments now through November 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 occur despite the best efforts of the Navy. Therefore, the proposed authorization allows for a small number of incidental injuries to marine mammals.

NOAA’s Fisheries Service 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:

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. Additionally, the proposed rule includes an adaptive management component that requires that the Navy and NOAA’s Fisheries Service meet yearly to discuss new science, Navy research and development, and Navy monitoring results to determine if modifications to mitigation or monitoring measures are appropriate.

NOAA’s Fisheries Service and the Navy have worked to develop a robust monitoring plan to 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. Additionally, the Navy is developing (with input from NOAA’s Fisheries Service) an Integrated comprehensive monitoring plan to better prioritize monitoring goals and standardize data collection methods across all of their U.S. range complexes.

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 using the identifier 0648-AW91.

NOAA understands and predicts changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.