Waveform selection for an electrically enhanced seine for use in harvesting channel catfish Ictalurus punctatus from ponds

A series of rapid screening trials was used to identify a waveform with the potential to repel channel catfish Ictalurus punctatus away from a seine. Waveforms were not considered effective unless they repelled catfish away f rom an advancing electrical array without causing electrotaxis, narcosis, o r observable injuries. Over 600 varying combinations of waveform types, vol tages, pulse frequencies, pulse widths, and pulse sweeps were evaluated in order to select the best waveform, for use in constructing an electrically enhanced seine. A number of electrode designs were evaluated to determine t he most efficient and effective electrode combination, size, and configurat ion to use in the screening trials. In studies conducted in concrete vats. harvest efficiencies (the percentage of fish present that were captured) gr eater than 92% were achieved using a low to high frequency waveform with a 6.060 Hz sweep and a 2 msec pulse width over a 4 sec sweep time. This wavef orm was selected for use in the construction of an electrically enhanced se ine that will be used in future pond harvest studies.