In three experiments, each with three species of newly transformed juvenile fishes, the immediate mortality was determined after electrical exposure to 60 Hz pulsed DC in waters of different conductivity ( C w ). With a constant applied power density ( D a ; 1·0–4·9 mW cm −3 depending on species) over a range of C w (10–1020 μS cm −1 ), the results predicted that the highest fish mortality would occur at C w of 65 μS cm −1 for...