Standardized and reproducible operating conditions as sampled distances, fishing season or dates, number of anodes, considered species, adjustment of power generators allowing the acquisition of coherent results and statistical analysis for scientific purposes. D... Biological issues- Salmonids show a greater reaction, for a given voltage, to a pulse rate of 50. s- 1 than one of 100. s- 1. Eels show the highest reaction to an electric field of around 20 pulses. s- 1. -3 LIFE4FISH.