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INSTRUMENTATION TO MONITOR LOCATION OF FISH CONTINUOUSLY IN EXPERIMENTAL CHANNELS
Citation:
Jahoda, J. INSTRUMENTATION TO MONITOR LOCATION OF FISH CONTINUOUSLY IN EXPERIMENTAL CHANNELS. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/3-77/035.
Description:
This study resulted in the development and construction of equipment to continuously monitor the position and temperature of up to 20 fish in a water channel 486 meters long, 3 meters wide, and 1 meter deep. The system uses miniature sonic transmitters (tags) operating in the 51 kHz to 366 kHz frequency range which were implanted in 500 gram or heavier fish. The battery operated tags were pulse modulated and designed for over 1 year operational life. A temperature sensitive thermistor controlled the repetition rate of the tag providing the temperature of the fish to an accuracy of 1 degree C. The nominal range of the polyurethane encapsulated tag was several hundred feet. Sixteen hydrophones were located at 30.5 meter intervals in the water channel. A control console contained a manually-operated, frequency-stepped receiver which could select any individual hydrophone, thus locating the fish to within plus or minus 15.25 meters. Up to 20 individual fish could be monitored. Automatic operation and recording of the data was considered in the design of the system for future equipment.