Cetacean Society International

Whales Alive!

Vol. VII No. 1 January 1998

Update on ATOC

by Brent Hall, CSI Board

As frightening as it is, the Navy's LFA/LFS project is not the only case where cetaceans are being deliberately exposed to potentially damaging noise. The Scripps Institution of Oceanography has been planning their Acoustic Thermometry of Ocean Climate (ATOC) Program for the past few years (see the previous Whales Alive! articles listed below). In this program, two fixed sound sources, one off the California coast and the other off Hawaii, are designed to inject a sound signal into the deep ocean channel so that it can be detected by hydrophones after traveling across the Pacific Ocean. The speed of the sound through the ocean provides an indirect indication of the water temperature, which may be used to study global warming or even El Niño (see the note below). Although the intensity of the sound is less than that used by the LFA/LFS, there is still concern that whales near the sources might be injured, and that the long-term injection of low-frequency sound waves into the deep ocean channel might affect whales' ability to communicate with each other over long distances, since it is thought that they use the channel for that purpose. Just as the LFA/LFS spun off a research program for the study of the effects of noise on marine mammals when scientists expressed their concerns about it, the ATOC program spun off the Marine Mammal Research Program (MMRP) for the same purpose. According to a 30 October 1997 press release from Scripps, the MMRP commenced acoustic transmissions at both the Hawaii and California sound source locations in early November. Scientists (led in California by Dr. Dan Costa of the University of California Santa Cruz, and in Hawaii by Dr. Adam Frankel of Cornell University) will assess the effects of the sounds on marine mammals. It remains to be seen whether this research program will yield any useful information, or whether the MMRP is simply a cynical scheme to appease those who have opposed the ATOC program on the basis of its potential danger to marine mammals.

Note: Since the stated intention of ATOC is to gather data about global warming by filtering out seasonal temperature variations, it is difficult to understand the mention of measuring El Niño in Scripps' 30 October 1997 press release.

Refer to the next article on ATOC: Two More Dead Whales Associated with ATOC, in Vol. VII No. 2, April 1998

Previous articles on ATOC:

Go to next article: Captive Cetaceans In Latin America And The Caribbean or: Table of Contents.

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