NOAA Fisheries announced recently final regulations requiring the United States Navy to implement protective measures during training and testing activities off the coasts of California and Hawaii and on the high seas of the Pacific Ocean to reduce the effects on marine mammals.
The Navy requested an authorization under the Marine Mammal Protection Act, because the sound generated by active sonar, the sound and pressure generated by detonating explosives, and other associated activities may affect the behavior of some marine mammals, cause a temporary loss of their hearing sensitivity or other injury.
NOAA Fisheries recently made a final determination that the effects of these Navy operations will have a negligible impact on the species or stocks involved. NOAA Fisheries is requiring that the Navy use mitigation measures designed to reduce impacts to marine mammals.
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 authorization allows for a small number of incidental injuries or deaths to marine mammals from sonar, as well as vessel strikes and explosions.
Under the authorization, the Navy will have to follow mitigation measures to minimize effects on marine mammals, including:
- establishing marine mammal mitigation zones around each vessel using sonar;
- using Navy observers to shut down sonar operations if marine mammals are seen within designated mitigation zones;
- using mitigation 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; and,
- designating a “Humpback Whale Cautionary Area” to protect high concentrations of humpback whales around Hawaii during winter months.
These measures should minimize the potential for injury or death and significantly reduce the number of marine mammals exposed to harmful levels of sound.
Additionally, the final rule includes an adaptive management component that requires that the Navy and NOAA Fisheries meet yearly to discuss new science, Navy research and Navy monitoring results to determine if modifications to mitigation or monitoring measures are appropriate.
NOAA Fisheries and the Navy have worked to develop a robust monitoring plan to use independent, experienced vessel-based marine mammal observers (as well as Navy observers), 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, an Integrated Comprehensive Monitoring Plan developed by the Navy (with input from NOAA’s Fisheries Service) will better prioritize monitoring goals and standardize data collection methods across all U.S. Navy range complexes.
NOAA, December 19, 2013; Image: NavyMil