HTML _ 95-603 - Acoustic Thermometry of Ocean Climate, Marine Mammal Issues
12-May-1995; Eugene Buck; 16 p.

Abstract: After global warming became a concern in the mid-1950s, researchers proposed measuring deep ocean temperatures to reveal any significant trends in core ocean warming. Acoustic thermometry can detect changes in ocean temperature by receiving low-frequency sounds transmitted across an ocean basin because the speed of sound is proportional to water temperature. Acoustic Thermometry of Ocean Climate, or ATOC, is an international program involving 11 institutions in seven nations. It is designed as a 30-month ¨proof-of-concept¨ project to provide data on possible global climate change, with funding provided by the U.S. Department of Defense. A Marine Mammal Research Program (MMRP) was established as part of ATOC, to assess the effects of ATOC sound signals on marine mammals. The proposed ATOC sources will be located 15 kilometers off the coast of Kauai, Hawaii, and near the Pioneer Seamount, approximately 88 kilometers west of Point Pillar, California. The California source was originally proposed 40 kilometers off the coast of Point Sur, California, in the Monterey Bay National Marine Sanctuary, but the Sanctuaries and Reserves Division of the National Oceanic and Atmospheric Administration did not concur in this proposal. A debate has arisen over ATOC's impact on marine mammals versus the benefits of better global warming information derived from ATOC. Among the concerns are questions regarding the effects of low-frequency sound (below 100 Hertz) on marine mammals, and the baseline data available on marine mammals near the proposed source locations. Moreover, concerns have been raised about baseline data available for other marine biota, such as fish and sea turtles. In response to concerns expressed by the public, environmental groups, and scientists, as well as by Members of Congress, the National Marine Fisheries Service (NMFS) held a series of public hearings on the Marine Mammal Protection Act (MMPA) permit applications by Scripps Institution of Oceanography for ATOC. Consequently, ATOC was delayed until draft environmental impact statements (EISs) could be prepared. The Office of Naval Research funded a National Research Council (NRC) investigation of current knowledge and research needs with respect to the effects of low-frequency sound on marine mammals. The NRC report, released in March 1994, concluded that the data were insufficient to determine the possible effects of low-frequency sound on marine mammals. The NRC report emphasized the need for further studies on wild marine mammal behavior and marine mammal audition, and a review of the MMPA scientific research permitting process. The lack of information regarding the effects of low-frequency sound on marine mammals is evident. Consultation with NMFS, the Marine Mammal Commission (MMC), and the MMRP Advisory Board led to including mitigation measures in the draft EISs to alleviate potential harm to marine mammals. MMRP and other component studies are expected to provide substantive information on the effects of low-frequency sounds on marine mammals. [read report]

Topics: Marine

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