This paper presents a type of electric barrier for fish, which can be used to deter fish from water intakes
and to guide them into fishpass channels. The barrier was designed to continuously generate an inhomogeneous
low-voltage (50–80V) electric field. It consists of two arrays of steel electrodes (positive and
negative) anchored to the substrate, with floating buoys attached at the top of each electrode to maintain
their vertical position. Field strength increases continuously from the positive electrode array toward
the negative electrodes. The resultant electric field does not stun fish, but stimulates their neuromuscular
system, allowing them to escape. With input power of 0.43–0.45 kWh and power consumption of
0.0018 kWm−2, the system is inexpensive to operate, and safer for fish and other aquatic organisms than
classic electric barrier designs. Laboratory tests of the barrier with 14 fish species of various sizes indicate
that for flow velocities less than 0.20 ms−1, 93.8–98.2% of the fish did not pass the NEPTUN barrier