PURPOSE: To achieve the recovery of a paralyzed fish and prevent a damage such as apparent death thereof by detecting the fish entering between electrode lines, which is paralyzed by an electric screen between the both electrodes and sink to the bottom of the sea, and extending the space between the both electrode lower parts.
CONSTITUTION: When fishes enter between electrode lines 1, 3 in a state where an electric screen of a determined electric field strength is formed between said electrode lines by an electric source 12, they are detected by detecting means 13, 14, which means then output to comparators 16, 17. A timer circuit 18 is operated by the build up to a higher level of the output of the first detecting means 13 to output a signal of T time H. Then the fishes entering between the electrode lines fall into a state of paralysis, often loosing swimming ability to sink to the bottom of the sea. These are detected by the second detecting means 14, and the H output is sent from the comparator 17. An AND gate 21 outputs a drive command signal of H by the H output of the timer circuit 18 and an inverter 20 and the H output of the comparator 17 to operate a moving motor 9, which extends the lower part space between the electrode lines to weaken the electric field strength, so that the recovery of the sunk fish is achieved.
MAEHATA HIDEHIKO
ARAI HIROSHIGE
SUYAMA HIROYUKI
TSUKAHARA MASANORI
