The floating suspended matter existing in seawater cooling water system the coagulant which can cohere and/or under existing of the metal ion, adding aliphatic 1st - 3 class amines, aliphatic diamine or the sea raw living thing adhesion inhibiter of the aliphatic 4th class ammonium salt to seawater cooling water system, continuous conversion method of the sea raw living thing adhesion prevention effect which features that it makes the sea raw living thing adhesion prevention effect continue by preventing the density decrease of the sea raw living thing adhesion inhibiter with the adsorption to the floating suspended matter of the sea raw living thing adhesion inhibiter.海水冷却水系に存在する浮遊懸濁物質を凝集し得る凝集剤および/または金属イオンの存在下に、脂肪族第1~3級アミン、脂肪族ジアミンまたは脂肪族第4級アンモニウム塩の海生生物付着防止剤を海水冷却水系に添加して、海生生物付着防止剤の浮遊懸濁物質への吸着による海生生物付着防止剤の濃度低下を防止することにより、海生生物付着防止効果を持続させることを特徴とする海生生物付着防止効果の持続化方法。
