MARINE MAMMAL COMMISSION - Annual Report for 1998 



Available information often is insufficient to 

 identify and make well-reasoned judgments concerning 

 the relative costs and benefits of human activities that 

 use and produce sounds that could affect marine 

 mammals and other marine species. The Marine 

 Mammal Commission, in consultation with its Com- 

 mittee of Scientific Advisors, reviews sound-produc- 

 ing activities that may adversely affect marine mam- 

 mals or other components of the ecosystems of which 

 they are a part and provides recommendations to the 

 responsible regulatory agencies on measures needed to 

 resolve uncertainties and to ensure that the activities 

 do not have significant adverse effects on marine 

 mammals or their habitats. The Commission's 

 recommendations with regard to requests for small- 

 take authorizations and assessment of the possible 

 effects of seismic surveys and other activities associat- 

 ed with offshore oil and gas exploration and develop- 

 ment are described in Chapter IX. Background 

 information and Commission actions in 1998 regard- 

 ing other sound-producing activities that could affect 

 marine mammals are described below. 



Acoustic Thermometry of 

 Ocean Climate Program 



In 1993 the Defense Department's Advanced 

 Research Projects Agency provided funds to Scripps 

 Institution of Oceanography for a proof-of-concept 

 study titled the "Acoustic Thermometry of Ocean 

 Climate (ATOC) Program. " The intent of the pro- 

 gram was to determine if transmission times of low- 

 frequency sounds across ocean basins could be mea- 

 sured accurately and used to detect changes in ocean 

 temperature possibly indicative of global warming. 

 The project involved installing and periodically 

 operating 260-watt low-frequency sound generators in 

 deep water 15 km (9.3 miles) north of Kauai, Hawaii, 

 and 40 km (24.9 miles) off Point Sur, California, and 

 monitoring the sounds at distant sites. 



As noted in previous Commission reports, avail- 

 able information was insufficient to determine how 

 ATOC sound transmissions might affect marine 

 mammals. Consequently, the ATOC program was 

 expanded to include a marine mammal research 

 program, and an advisory board of scientists not 

 associated with the program was established to pro- 



vide advice on study design. Several scientists and 

 envirorunental groups questioned whether the pro- 

 posed research would resolve the uncertainties con- 

 cerning the possible effects of the ATOC program on 

 marine mammals and other marine organisms. They 

 urged that the proposed marine mammal research 

 program and related environmental impact statements 

 be revised and expanded to ensure that the possible 

 environmental impacts of the planned ATOC sound 

 transmissions in both California and Hawaii were 

 identified and objectively evaluated. 



In response, the Advanced Research Projects 

 Agency prepared environmental impact statements for 

 both the California and Hawaii components of the 

 ATOC program. In addition, the ATOC principal 

 investigator applied for and received permits from the 

 National Marine Fisheries Service authorizing the 

 taking of marine mammals in the course of the 

 planned ATOC marine mammal studies. The Marine 

 Mammal Commission's comments and recommenda- 

 tions on the environmental impact statements and the 

 scientific research permits are described in previous 

 Commission reports. 



The ATOC sound source on the Pioneer Seamount, 

 off central California, was installed in October 1995. 

 The source off Kauai was installed in October 1996. 

 The marine mammal studies were expected to be 

 completed by December 1997. However, both sound 

 generators failed to work properly and had to be 

 repaired. Consequently, some aspects of the marine 

 mammal research program could not be completed in 

 1997, and the permits authorizing the studies were 

 extended through December 1998. No additional 

 funding was provided and the data collection aspects 

 of this program were terminated in 1998. The study 

 results are expected to be reviewed by the marine 

 mammal program advisory board in the spring of 

 1999 and to be made public shortly thereafter. 



Reports submitted to the National Marine Fisheries 

 Service, as required by the scientific research permits 

 issued by the Service, indicate that the ATOC sound 

 transmissions have had few detectable effects on 

 marine mammals and that the effects appear biologi- 

 cally insignificant. A paper by the ATOC Consortium 

 — titled "Ocean Climate Change: Comparison of 

 Acoustic Tomography, Satellite Altimetry and Model- 



166 



