Assessment of phytoplankton and water quality of Sariyar, Gokcekaya and Yenice Dam Lakes (Eskisehir, Ankara)

Abstract

In this study, it was aimed to determine the phytoplanktonic algal flora and trophic level using a phytoplankton-based index of three interconnected dam lakes. Phytoplankton samples were collected from five study sites in the Sariyar dam and one site each in the Gokcekaya and Yenice dams. Phytoplankton sampling was carried out in two periods in August and November 2016. Some physicochemical variables were sampled monthly between June 2016 and May 2017. The annual average electrical conductivity was determined to be over 1000 mu S/cm in all three dam lakes. According to Kruskal-Wallis analysis, ammonium nitrogen significantly decreased from Sariyar Dam to Yenice Dam, however, nitrate nitrogen showed a statistically significant increase. While a total of 144 algal taxa were identified, 73 taxa were detected in Yenice, 64 in Gokcekaya, and 108 in Sariyar. Detrended correspondence analysis results revealed the spatial distribution of the phytoplanktonic taxa. The highest taxa number was determined as Chlorophyta with 69 taxa, followed by Bacillariophyta with 38 taxa. When the phytoplanktonic algal flora was compared with previous studies, 95 taxa were found to be new records for these three interconnected dam lake systems. The phytoplankton trophic index results showed that the biological quality range was poor status in all three dam lakes. It has been concluded that Sariyar, Gokcekaya, and Yenice dam lakes cannot be evaluated as suitable for trout farming activities planned to be carried out in the dam lakes.