Northern Prairie Wildlife Research Center
Thomas F. Norris, Bio-waves, 8455 Kingsland Road, San Diego, CA 92123 USA, Marco Flagg, Desert Star Systems, 761 Neeson Road, Suite #9, Marina, CA 93933 USA, and Donald Croll, Institute of Marine Sciences, University of California, Santa Cruz, CA 95060 USA
We are developing a tracking/telemetry system for real-time monitoring and recording of underwater movements and behaviors of whales from a moving vessel. This Ultra Short BaseLine (USBL) based system consists of an acoustic transponder "tag" (attached to animal) that produces a high frequency acoustic signal upon interrogation from a boat-based surface station. The PC-based surface station computes underwater locations based upon signal return-time and phase information from the tag's signal. A CMOS microprocessor in the tags controls its basic functions including the capability of receiving up to seven channels of data (e.g. temperature, swim velocity, sound levels) acoustically transmitted from the tag. These data also can be stored internally in the tags RAM memory. The tag also contains a small radio-transmitter for tracking animals at the surface (in-air), and a radio-signaled release mechanism for tag retrieval. At present, this system is being tested for use in the open ocean to study large balaenopterid (e.g. blue and fin) whales.