Chapter VI — Effects of Pollution 



ing" — published in the 28 August 1998 edition of 

 Science suggests that the program could provide 

 insight into ocean changes caused by global warming. 

 At the end of 1998 the Commission knew of no plans 

 or funding requests to continue the ATOC program. 



Low-Frequency Active Sonar 



On 18 July 1996 the Department of the Navy 

 published a Federal Register notice announcing its 

 intent to prepare environmental impact statements on 

 operational deployment of a surveillance towed array 

 sonar system (SURTASS) low-frequency active (LFA) 

 sonar. The notice indicated that the system used 

 propagated low-frequency sound (<1000 Hz) to 

 detect objects on and under the sea and that the Navy 

 proposed to make the system available to fleet com- 

 manders "for world-wide employment to enhance 

 antisubmarine capability." The Federal Register 

 notice requested information and views on issues to be 

 addressed in the environmental impact statements. 



As noted in its previous report, the Marine Mam- 

 mal Commission, in consultation with its Committee 

 of Scientific Advisors, advised the Navy by letter of 

 4 September 1996 of issues that it believed should be 

 addressed. The Commission concurred with the view 

 expressed in the Federal Register notice that many of 

 the possible adverse effects on marine mammals might 

 be avoided or minimized by combinations of mea- 

 sures, such as identifying and avoiding particularly 

 sensitive species and areas. The Commission pointed 

 out that, in some cases, available information may be 

 insufficient to make reasoned judgments concerning 

 possible adverse effects. For example, if the hearing 

 ranges and thresholds of potentially affected species 

 are unknown, it would not be possible, except by 

 analogy with similar species whose hearing ability is 

 known, to make reasonable judgments as to the 

 distances at which the species might detect and 

 possibly be affected by the LFA sonar transmission. 

 In this regard, the Commission pointed out that the 

 environmental impact statements should clearly 

 identify any uncertainties and assumptions about the 

 possible impacts of the proposed action and alternative 

 actions on marine mammals and other biota. 



On 8 January 1997 the Navy held a meeting to 

 review comments provided by the Commission and 



others. Many of the meeting participants expressed 

 the view that available information was insufficient to 

 accurately assess the possible environmental impacts 

 of the proposed action, and they suggested that the 

 Navy consult scientists not associated with the Navy 

 to identify the information needs and how best to meet 

 those needs. In response, the Navy constituted a 

 scientific working group composed of government and 

 non-government scientists to provide advice on needed 

 research and to help evaluate the results of that 

 research. Representatives of the Commission serve on 

 this working group. 



As noted in the Commission's previous annual 

 report, the Navy, based on input from the scientific 

 review group, developed and in 1997 began imple- 

 menting a three-phase research program to determine 

 how representative marine mammal species respond to 

 the LFA sonar transmissions. The studies have been 

 done by a team led by scientists from Cornell Univer- 

 sity and Woods Hole Oceanographic Institution. 

 Phase I of the experimental program, conducted off 

 San Nicolas Island in southern California in Septem- 

 ber and October 1997, focused on blue and fin whales 

 feeding in the area at that time of year. Phase II, 

 undertaken in December 1997, focused on gray 

 whales migrating along the coast of central California. 

 Phase III was done in February and March 1998 and 

 focused on humpback whales that mate and raise 

 calves in waters around the main Hawaiian Islands 

 during winter. 



The Navy held a meeting on 30 June 1998 to 

 advise the public and interested government and non- 

 government organizations of the results of the re- 

 search program and plans to prepare an environmental 

 impact statement on the proposed deployment of the 

 SURTASS LFA sonar. On 15-16 September 1998 

 the Navy convened the scientific review group to 

 assess the usefulness of research results and ongoing 

 efforts to analyze and report the resulting data. 

 Commission representatives attended both meetings. 



The results of the meetings and related information 

 were reviewed by the Commission and its Committee 

 of Scientific Advisors during their annual meeting in 

 Portland, Maine, on 10-12 November 1998. Infor- 

 mation presented at the meeting indicated that the 

 experiments detected few effects on marine mammals, 



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