CULTURE OF TUNA USING MEANS FOR PREVENTING ADHESION OF MICROORGANISM, BARNACLE, OR THE LIKE TO FISHING NET AND FISHING GEAR, AND DEVICE THEREFOR

PROBLEM TO BE SOLVED: To provide a means for preventing the adhesion of microorganisms, barnacles, etc. to fishing nets or fishing gears, and also to provide culture of tunas, which enables a user to cultivate tunas even in a fish preserve net shaped like a circle of 10 m in diameter and 10 m in depth or a square of 10 m×10 m, and a device therefor, though it is regarded that the culture of young yellowtails, red sea breams, tunas, etc. using a fish preserve net is difficult since tunas often die due to their collision against a fish preserve unless the fish preserve net has a size of 20 m or over in diameter and 10 m in depth.SOLUTION: A polyethylene fiber which is made by mixing chlorine or calcium hypochlorite with a polyethylene resin, or a polyethylene fiber in which chlorine or calcium hypochlorite is kneaded inside, is used for yarn used for fishing nets or fishing gears. Alternatively, an obstacle 12 such as a white float 2, a white pseudo tangle weeds 11, or the like is formed inside the fishing preserve net 1 for cultivating tunas, or the fishing preserve net 1 is made of conductive mesh, and AC or DC is let flow to form a protective barrier of current inside the fishing preserve net 1.