水島地区の水質汚濁,特に異臭魚の発生に関する研究 第1報 異臭魚の分布状況について

The distribution of abnormal odor fish owing to industrial waste water from oil or its combinative industrial factories around the Miziushia waters was surveyed and the followings were obtained as the result. 1) It was found that almost all of abnormal odor fishes in the Migushima waters grow around the Mizushima harbour where many exits of industrial waste water from factories are gathered. The area of the distribution is beconing more extensive with the degree of 1 or 2 Km. every year, and it has stretched 8 Km. to the south and 12 Km. to the west around the Mizushima harbour. 2) Fishes having the high swimmung activity (ex. common sea-bass, gizzard shad and gray mullet etc.) were found as abnormal odor fishes as far as the border of the distribution area, and fishes having the low activity (ex. rock, bleak sea-bream and surf-fish etc.) were found within 1 Km. from the mouth of the harbour. And the following is thinkable that fishes gather to the warm water of the Mizushima harbour owing to the high temperature of waste water of factaries and there become abnormal odor fishes, and in spring when water becomes warm, they scatter away from the harbour.