Cyrus Bazeghi
Dept. of Comput. Eng., Univ. of California, Santa Cruz, CA 95064
Guy W. Oliver
Univ. of California, Santa Cruz, CA 95064
Development of the movement and position (MAP) tracking system was motivated by limitations of currently available tags for marine mammals. The MAP tag employs a global positioning system (GPS) receiver to accurately fix an animal's position when it surfaces and a tri-axial magnetometer and velocity-time-depth recorder to track in three dimensions underwater movements between surfacings. The tag is microprocessor controlled allowing flexibility and user control of sampling regimes. Data are stored in a high capacity datalogger. To minimize the energy budget the GPS receiver is only switched on when the animal nears the surface and switched off when a fix is obtained. The unit is battery-powered, self-contained and capable of deployment on animals descending to 1500 m. By attaching a pinger to the animal it can also be tracked acoustically, allowing calibration of passive acoustic tracking systems. In its current configuration, the MAP tag is designed for deployment on elephant seals, but with relatively minor reconfiguration of the package it could be deployed on many large marine vertebrates. It is anticipated that the capability of the MAP tag will dramatically enhance future studies of marine mammal behavior, navigation, orientation, and foraging. [Work supported by ONR.]