WASHINGTON, D.C. -- NOAA’s Fisheries Service has issued regulations and a letter of authorization to the U.S. Navy to impact marine mammals while conducting training exercises around the main Hawaiian Islands. The regulations require the Navy to implement measures designed to protect and minimize effects to marine mammals.
The Navy requested authorization under the Marine Mammal Protection Act because the mid-frequency sound generated by tactical active 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.
NOAA’s Fisheries Service does not expect the exercises to result in serious injury or death to marine mammals, and is requiring the Navy to use mitigation measures intended to avoid injury or death. However, in a small number of cases, exposure to sonar in certain circumstances has been associated with the stranding of some marine mammals, and some injury or death potentially could occur despite the best efforts of the Navy. Therefore, the regulations and the letter allow for incidental impacts on marine mammals, including injury or death of up to 10 animals of each of 11 species over the five years covered by the regulations.
NOAA’s Fisheries Service has determined that these effects would have a negligible effect on the species or stocks involved.
Under the regulations and the letter, the Navy must 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.
NOAA’s Fisheries Service and the Navy worked to develop a robust monitoring plan to use independent, experienced aerial and vessel-based marine mammal observers (as well as Navy watch standers), passive acoustic monitoring, and tagging 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 letter.
The Navy has been conducting training exercises, including the use of mid-frequency sonar, in the Hawaiian Islands for more than 40 years. Exercises range from large multi-national, month-long training exercises using multiple submarines, ships, and aircraft conducted every other year, known as Rim of Pacific Training Exercises, to two- to three-day exercises to test the readiness of battle groups, known as Undersea Warfare Exercises or USWEXs, and shorter exercises that last less than a day. In addition, some exercises involve the use of explosives.
This regulation, in effect for five years, governs the incidental take of marine mammals during the Navy’s training 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.
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.
Views expressed in this article do not necessarily reflect those of UnderwaterTimes.com, its staff or its advertisers.