Catch selectivity by electrical fishing systems

Abstract

Electric fields affect large fish more strongly than small fish. Electrical fishing systems should preferentially capture the larger members of a fish stock, but in practice their selectivity is controlled by the uniformity of the electric field distribution and the particular fish reaction to electrical stimulation being exploited. From published data, the selectivity of a practical system is evaluated for various electric field distributions and types offish reaction. It is found that the probability of capture by the system increases with fish size, but with a high electric field strength the system can be non-selective.