Christopher W. Clark
David K. Mellinger
Cornell Lab. of Ornithol., Bioacoust. Res. Prog., 159 Sapsucker Woods Rd., Ithaca, NY 14850
The recent application of Navy Integrated Undersea Surveillance System (IUSS) data (Whales `93) for detecting and tracking low-frequency sounds from whales has led to a renewed interest in the use of these arrays for marine mammal research. Previous work with sparse arrays has limited the detection and tracking to ranges of tens of kilometers, while the IUSS allows for orders of magnitude greater coverage. SOSUS data are processed via computer systems specifically developed for detecting and tracking whales, as well as through annotations, to determine individual, geographic, and seasonal variability in vocalizations for at least four species (blue, finback, humpback, and minke), and there are also numerous sounds from unidentified whales. Given that these animals use these deliberate patterns of intense low-frequency sounds for either communication, navigation, or food finding, verification of sound function will be deduced through careful examination of behavioral context and other environmental conditions such as local productivity, bathymetry, and oceanography. Results from the Whales `93 and continuing Dual Use projects will be presented. This will include descriptions of signal variability for the different species of marine mammals and preliminary interpretation of the results in terms of sound function. [Work supported by ONR and NRL.]