Effects of Environmental Factors on the Seasonally Change of Chlorophyll-a in Eutrophic Plateau Lake Dianchi, China

The eutrophication of lake and followed cyanobacteria bloom are the most apparently eco-environmental problem in freshwater lakes in China. Lake Dianchi is the largest and the most serious eutrophic freshwater lake in southwest China that has experienced cyanobacterial blooms annually during the last few decades. The temporal distribution of phytoplankton biomass (estimated using chlorophyll-a concentration) and its correlation with related physical and chemical viriables including water temperature, pH, total phosphorus(TP) and total nitrogen(TN) in Lake Dianchi were investigated from March 2009 to January 2010. Due to the combined effects of high temperature, nutrient conditions and neutral to alkaline pH values in this lake, the phytoplankton biomass were higher and more uniform compared to other cyanobacterial blooms reported in temperate regions. This study advances our understanding of nutrient enrichment and high water temperature influences on phytoplankton biomass.