The physical factor influencing blooming of phytoplankton in Menjer Lake Wonosobo Indonesia

Phytoplankton are organisms that are sensitive to environmental changes and their presence can be used as an indicator of aquatic productivity. Physical factors in the waters can affect the abundance of phytoplankton. The purpose of this study is to determine the relationship between physical factors (temperature, brightness, TDS and TSS) and the abundance of phytoplankton. Phytoplankton sampling was carried out at 7 stations by purposive random sampling in Menjer Lake including 7 sites of the tourism areas, floating net cages, near agricultural areas, the middle of the lake, spring sources, inlets of the Serayu River and outlet areas. The variables measured were temperature, light penetration, TSS and TDS concentration as well as the composition and abundance of phytoplankton. The results of this study obtained 6 species of phytoplankton, namely Ceratium sp., Dictyosphaerium pulchellum, Microcystis aeruginosa, Microspora sp., Nitzschia sp., and Pediastrum sp. The highest abundance of phytoplankton is Microcystis aeruginosa and temperature in related to season has a strong effect on the abundance of phytoplankton.