NOAA Gives Navy Marine Mammal Protection Measures for Exercises off the Gulf Coast

January 21, 2010

Right whale and calf.
Right whale and calf.

High resolution (Credit: NOAA)

NOAA’s Fisheries Service has issued regulations and a letter of authorization to the U.S. Navy that includes measures to protect marine mammals while conducting naval exercises off the Gulf of Mexico coast. The regulations require the Navy to implement measures designed to protect and minimize effects to marine mammals.

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

NOAA’s Fisheries Service does not expect the test and evaluation activities to result in serious injury to marine mammals. However, NOAA is requiring the Navy to use mitigation measures because exposure to nearby underwater detonations can injure marine mammals, and some injury could occur despite the Navy’s best efforts. The proposed authorization allows for a small number of incidental injuries to marine mammals.

NOAA’s Fisheries Service has determined that these effects would have a negligible effect on the species or stocks involved.

Under the authorization, the Navy is required 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 regulations and authorization include a requirement 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 help better understand how marine mammals respond to various levels of sound, and to assess the effectiveness of mitigation measures. The implementation of this monitoring plan is included as a requirement of the regulations and the authorization. Additionally, the Navy, with input from NOAA’s Fisheries Service, is developing an integrated comprehensive monitoring plan to standardize data collection methods across all of their U.S. range complexes and study areas.

The Navy has been conducting research, development, test and evaluation activities, including the use of active sonar and explosives, in the Gulf of Mexico for more than 60 years. The naval activities provide test and evaluation and in-service support for expeditionary maneuver warfare, operations in extreme environments, mine warfare, maritime operations and coastal operations. A variety of naval assets, including vessels, aircraft and underwater systems support these mission activities for eight primary test operations including air, surface, and subsurface operations, sonar, electromagnetic energy, laser, ordnance and projectile firing.

This regulation, in effect for five years, governs the incidental take of marine mammals during the Navy’s test and evaluation activities, and includes required mitigation and monitoring measures. The letters of authorization, which are required for the Navy to legally conduct their activities, are issued annually, provided the Navy abides by the terms and conditions of the letter, submits the required annual reports, and shows their activities do not result in more numerous effects or more severe harm to marine mammals than were originally analyzed or authorized.

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