Investigating the Effect of Palangan fish Farms on Water Quality of Sirvan River Using Physicochemical and Biological Indicators

The effect of Palangan fish farms on water quality of Sirvan River was investigated using physicochemical and biological indicators from January 2015 to June 2015. Five stations were determined including 1) before the fish farm 2) after the fish farm effluent 3) sub-branch 4) 100 meter after fish farm effluent and 5) 1000 meters after fish farm effluent. EC showed significant differences in different stations and seasons (P<0.05), but the amounts of temperature, pH and DO showed only seasonal effects (P<0/05) and the levels of ammonia onlyshowed significant differences among different stations (P<0.05). Other parameters showed no significant differences in stations or seasons (p>0.05). According to the water quality index (WQI), the water quality of Sirvan River was better in spring compared to winter. Biological indices including EPT and the frequency were not significantly difference in different seasonal and stations (p>0.05). However, the lowest frequency and EPT index were obtained at 100 meter after fish farm effluent. In conclusion, the results of this study showed that effluent of fish farms in the Sirvan River can be affected in the shortest distance, but water quality becomes acceptable far from the effluent of fish farms. Also, EPT richness and frequency indices confirmed the effects of fish farms effluent on water quality of Sirvan River.