Biology of Cetaceans Studied in Concert with RIMPAC Sonar Exercises

During the Sette expedition, this male pilot whale was outfitted with a d-tag to collect data on the animal's movements.

In July 2008, the PIFSC Cetacean Research Program joined partner institutions in a project to study how deep diving marine mammals dive, feed, interact with one another and respond to sounds in their environment. Cooperating with PIFSC researchers were colleagues from the University of Hawai'i, Cascadia Research Collective, Woods Hole Oceanographic Institution, Wild Whale Research Foundation, and Duke University.

Operating from the NOAA Ship Oscar Elton Sette and smaller launches, the scientists placed two kinds of monitoring tags (d-tags and satellite tags) on deep-diving beaked, pilot, and melon-headed whales. The d-tags recorded detailed information on short-term movement of the cetaceans and the sounds they produce and hear. Satellite tags provided longer-term data on movement of the cetaceans around the Hawaiian Islands.

In addition to attaching monitoring tags to cetaceans, scientists collected a variety of environmental data to relate movements of the marine mammals to their prey and physical characteristics of their habitat. Vertical profiles of ocean temperature and salinity were recorded by deploying CTD and XBT instruments, and fisheries acoustics instruments were used to measure the density of prey organisms in the water column.

As a pilot project, these scientific operations were conducted in conjunction with the Navy's Rim of the Pacific (RIMPAC) 2008 exercises around the Hawaiian Islands. U.S. Navy vessels participating in RIMPAC operations use mid-frequency active sonar for anti-submarine warfare training. Sound emitted from active sonar can affect the behavior and well being of marine mammals but adequate data on impacts are lacking. The research by the Sette in concert with RIMPAC training was an important first step in scientifically addressing this issue.

For more information contact: Marie Chapla