Effects of the California ATOC experiment on marine mammals

The effect of the California ATOC experiment on marine mammals has been studied using aerial surveys to observe changes in marine mammal abundance. Dramatic changes in behavior have not been observed while the source was operating. The following species have been sighted in the area humpback, sperm, gray, fin, pilot, and killer whales, Baird’s and Cuvier’s beaked whales, elephant seals, California sea lions, northern fur seals, Risso’s, Pacific white-sided and northern right whale dolphins, and Dall’s porpoise. Satellite and archival tags were used to record the behavior of elephant seals as they passed by the ATOC sound source. Tracks of male elephant seals passing by the Pioneer Seamount were closer on their return migration when the source was on than on their outbound path when the source was off. Acoustic data loggers were deployed on juvenile elephant seals that were released by boat near the ATOC sound source. These units collected data on diving and swimming behavior concurrently with recordings of the ATOC source sound pressure level at the animal. [Work supported by the Strategic Environmental Research and Development Program through ARPA and the Office of Naval Research.] 43.30.Sf