Abstract
In the Inland Sea of Japan, with increasing the inflow of nitrogen and phosphorus phytoplankton proliferated, resulting in deterioration of water quality. The water area what is called eutrophication is progressing was investigated.
In 1995, red tide appearance was observed in Okayama prefecture. Damage was not done to fishery but it is necessary to pay attention. Skeletonema costatum, it's phytoplankton was observed in sea water of a bathing resort in Okayama Prefecture. COD was increased to 3.1 (mg·l-1).
Kojima lake is a man-made fresh-water lake and values of water quality parameters for instance COD, T-N, T-P, are two times as much as environmental standards. During summer in 1995, fresh waterred tide was observed and characterized by the appearance of Aphanocapsa rivularis and Anabaena spiroides at the point of Himon in Kojima Lake. And it needs to survey the mechanism of burst appearance.
