The Effects of Physico-Chemical Parameters on the Phytoplankton Population of Shahrchai Dam Reservoir (Uramia- Northwest Iran)

The effects of water physico- chemical factors on phytoplankton communities of Shahrchai dam reservoir were studied. 6 sampling sites were chosen along Shahrchai dam and surface and deep layers were sampled during 3 seasons in 2015-2016. In this study, phytoplankton samples were fixed with 4% formalin and transferred to laboratory. Identification and enumeration of the phytoplankton were performed by inverted microscope equipped with 5 ml counting chamber. Totally 34 species of phytoplankton belonged to Green algae, Diatomes, Cyanobacteria and Euglenophyta were determined. Statistical analysis was carried out by PCA and UPGMA methods. The analysis of data by PCA showed that first and second axis created 99% of changes alone. There were 3 completely distinct groups of samples regarding the sampling seasons. The most effective physico- chemical factors influenced the phytoplankton communities were water transparency, EC and water temperature.