The effects of physicochemical parameters on fish distribution in Eğirdir Lake, Turkey

Abstract

The present study was conducted based on the fish species and physicochemical parameters of Eğirdir Lake. Sampling was carried out monthly from January through December 2010 between 9 am and 11 am. The parameters measured were water temperature, depth, secchi disk depth, turbidity, dissolved oxygen, saturation of dissolved oxygen, pH, conductivity, chloride, hardness, calcium, magnesium, bicarbonate, carbonate, nitrate, nitrite, ammonium, sulphate, phosphate, silica, organic substance, acid power (SBV) and chlorophyll-a. Monthly sampling was performed at four stations at different depths. Water temperature ranged from 6.9±0.5 °C in February to 26.8±0.4 °C in August. Minimum secchi disk depth recorded was 0.5 m while the maximum was 2.4 m. Dissolved oxygen ranged from 4.2±0.2 to 12.6±0.6 mgL-1. The pH values ranged from 8.4 to 9.6. In this study, 15 fish species, belonging to eight families were identified. Among the 15 fish species recorded, Cyprinidae was the dominant family followed by Percidae (3 %). According to detrended correspondence analysis (DCA), variables were able to explain 90 % of total variation suggesting a significant result. The results showed that water temperature, dissolved oxygen and saturation of dissolved oxygen were the most important physicochemical parameters affecting fish distribution. Other pyhsicochemical parameters of this lake did not show any significant statistical differences in determining fish distribution.