[Eutrophication and Characteristics of Cyanobacteria Bloom in the Summer in Guishi Reservoir].

. The cell density decreased over time and concentrated on the surface and at the depth of 2 m underwater. The total phytoplankton cell density was strongly correlated to total phosphorus, total nitrogen, nitrate nitrogen, and the permanganate index, and was inversely correlated to transparency. The water in the Guishi Reservoir was not polluted by microcystic toxins. Moreover, Guishi Reservoir is in a meso-eutrophic state; therefore, the prevention and control of the cyanobacteria bloom should focus on weather conditions and on reducing the input of nitrogen and phosphorus to keep the nutrient levels low.