METHOD FOR PREVENTING BITING DAMAGE OF FISH ON CULTURED LAVER AND APPARATUS THEREFOR

PROBLEM TO BE SOLVED: To provide a new technique to stabilize the laver culture by preventing the biting damage of fish at a low cost and effective for solving the problems of conventional technique comprising the spreading of biting damage from the initial stage of seed culture of laver cultivation by fishes eating the young sprout on a laver net and the following eating damage by fish to cause destructive damage on the laver culture, and solve the problem of conventional protection net for striped mullet, black porgy, rabbitfish, etc., to prevent the intrusion of the fish by encircling the laver net comprising the requirement for enormous expense and labor and the lowering of the laver quality by the obstruction of tidal current to lose the profitability of laver culture. SOLUTION: Totally waterproof submerged loudspeakers are properly submerged in the sea at the position of laver net, an underwater sound transmission instrument such as dedicated amplifier for submerged loudspeaker is placed on a buoy, etc., on the sea, signal of fish-repelling sound such as the sound of dolphin, siren, knocking noise, etc., is transmitted from the sound transmission instrument at regular intervals and the sound is generated from the submerged loudspeakers to prevent the biting damage of fish on the cultured laver. The fish damage preventing apparatus is composed of the instrument and a power source to actuate the instrument.