Phytoplankton Assembly Effect in Karaj Reservoir Water Quality

Phytoplankton plays a major role in monitoring aquatic ecosystems. The purpose of this study was to investigate the relationship between the density of phytoplankton and the nutrients, especially nitrates and phosphates and other effective parameters in Karaj dam as a case study. For this purpose, in 2010, Karaj dam was sampled during a year and physical, chemical and biological factors were measured. The penetration depth of sunlight into the water, was measured using Sechei disk. The results of this study demonstrated that there is a thermal stratification in Karaj reservoir. The density of phytoplankton in this lake increased in hot weather of the year and it also varies as the depth increases. In 2010, the most population in phytoplankton community of the lake was formed by Diatoma and specially Cyclotella. No relationship was found between the number of phytoplankton and the amount of chemical factors in this study.