Comparative Study on the Phytoplankton in the Middle and Lower Reaches of Yalu River, Liaohe and Dalinghe Valley

th , 2014 Abstract The current species composition, standing crop and distribution, ect. on the phytoplankton were investigated and studied in the waters of the Northwest of Liaoning Province water supply project, during May to June in 2010. The water supply project consists of the water supply (the middle and lower reaches of Yalu River) and water benefited areas (Liaohe and Dalinghe River). There were 241 species of phytoplankton, which belonged to 91 genera of 8 phyla. The overall evaluation suggested that the water supply area could be delimited to os-β-ms level and the water was pol- luted slightly. However, the water benefited area could be delimited to β-α-ms level; the water was medium-polluted; and the eutrophication was more serious in some regional water.