DATAANALYSIS ON RELATIONS BETWEEN WATER QUALITYAND PHYTOPLANKTON GROWTH IN RESERVOIRS

Abstract

Eutrophication is one of the major issues inmanagement of reservoirs, so that it is important to know water quality conditions toencourage significant algal growth. In this study, relationsbetween water quality and algal growth are investigated usingdatafromliterature and database ofreservoir water quality from all over Japan. The following conclusionsare obtained: 1) Blue-green algae, especially Microcystis, tend togrow significantly inhigh water temperature conditions. 2) Blue-green, which isa major water bloom forming species, does not necessarily have larger growth rate thanother species. They seem to win toform water bloom. 3) Each algal species seem to have different optimum condition to grow. For example, blue-green tend togrow in conditions ofhigher water temperature and higher nutrient concentration, while diatom grow in lower water temperature and lower nutrient concentration.