The Seasonal and Spatial Distribution of the Phytoplankton of a Mesotrophic Lake Related to Certain Physical and Chemical Parameters

The seasonal and spatial distribution of the phytoplankton and their relationship with physicochemical parameters of Lake Poyrazlar, a mesotrophic lake located in Northwest Turkey, was studied monthly between April 2011 and March 2012. A total of 120 taxa in 7 divisions were identified during the study. The planktonic algae of Lake Poyrazlar was dominated by Cyanobacteria in the summer, Charophyta in the fall, diatoms and Cryptophyta in the winter, and Chlorophyta in the spring. The relationships between water temperature, pH, specific conductance, dissolved oxygen, Secchi disk depth (transparency), Chl-a, nitrate-nitrogen (NO3-N), nitrite-nitrogen (NO2-N), total phosphorus (TP), orthophosphate (PO4-P), silica (Si), sulfate (SO4) concentrations, and the abundance of dominant species were explored using the statistical method of Canonical Correspondence Analysis (CCA). The CCA results showed that the most important factors affecting the distribution of phytoplankton were the concentrations of the main nutrients, water temperature, and underwater light.