TUNA CULTIVATION USING MEANS FOR PREVENTING ADHESION OF MICROORGANISM, BARNACLE AND THE LIKE TO FISHING NET AND FISHING IMPLEMENT AND APPARATUS FOR THE SAME

PROBLEM TO BE SOLVED: To provide a means for preventing adhesion of microorganisms, barnacles and the like to a fishing net and fishing implements, and to provide tuna cultivation and an apparatus for tuna cultivation which enable cultivation using a fish preserve net formed in a cylindrical shape having a diameter of 10 m and a depth of 10 m or a quadrangular shape of 10 m square, although in cultivation of young yellowtails, bream, yellowtails, and the like using a fish preserve net, tunas are difficult to cultivate since tunas frequently collide with a fish preserve net to die when the fish preserve net is smaller than a net whose diameter is 20 m or more and whose depth is 10 m.SOLUTION: A polyethylene fiber made by being mixed with chlorine or calcium hypochlorite or a polyethylene fiber where chlorine or calcium hypochlorite is kneaded inside the fiber is used as a yarn used for a fishing net and fishing implements. White floats 2 and obstacles 12 such as white artificial laminaria 11 are formed inside the fish preserve net 1 for tuna cultivation. The fish preserve net 1 is formed of a wire net having electrical conductivity, and a direct current or an alternating current is applied to form a defensive wall of electric current inside the fish preserve net 1.