We evaluated the feasibility of an electro-fishing system using numerical simulations for laboratory tanks
and the open sea. A non-homogeneous bi-dimensional electric-field model for water and fish based on discrete
formulation of electro-magnetic field equations was developed using GAME (geometric approach for
Maxwell equations) software. Current densities (μA/cm2) and voltage differences (V/m) were calculated
for a fixed shape and spatial geometry of electrodes (one circular anode central to two symmetric linear
cathodes 10 m distant from each other). Voltage gradients inside the fish and close to the body (head–tail
potential difference and mean, maximum and minimum field modules) were determined. Tank and open
sea environments were numerically described for single fish 10 cm or 30 cm long and for groups of 30
fish 10 cm long. In the open sea, a tension of 90 V at the electrodes and a water conductibility of 5 S/m
resulted in an area of fish attraction (voltage gradient >10 V/m) of about 30 m2. Fish in the open sea and
in groups had greater internal voltage differences than did fish in tanks and single fish.
