SPATIAL AND TEMPORAL DISTRIBUTION OF PHYTOPLANKTON IN KARKAMIS DAM LAKE (SANLIURFA/TURKEY)

The environmental factors that affect the seasonal change of the phytoplankton community and composition in Karkamis Dam Lake were investigated on samples taken from five stations between January 2015 and December 2015. It was found that the phytoplankton of Karkamis Dam Lake consisted of 85 taxa belonging to Bacillariophyta (56 taxa), Chlorophyta (15 taxa), Chrysophyta (1 taxon), Cyanophyta (10 taxa), Dinophyta (2 taxa) and Euglenophyta (1 taxon). Members of Bacillariophyta and Chrysophyta increased well during spring, summer and also at the end of fall whilst Chlorophyta grew well only in summer and fall. Cyanophyta became dominant at the end of spring and in summer. However Dinophyta was remarkably conspicuous in winter as well as in spring and fall in terms of prevalence. Excessive reproduction of Cyanobacteria, which is a characteristic aspect of mesotrophic lakes, was observed in Karkamis Dam Lake in both May and July. Results of physical and chemical measurements and analysis indicated that the lake was mesotrophic based on PCA and Carlson trophic state index. Phytoplankton composition was found to be affected by environmental factors such as temperature, pH, dissolved oxygen, phosphate and nitrate through the year. Using these data, a strong model was developed for sustainable management in Karkamis Dam Lake.