مقايسه فاكتورهاي فيزيكي و شيميايي آب قبل و بعد از مزارع پرورش ماهي قزل آلا در رودخانه دو هزار تنكابن

Comparison of physicochemical factors for inlet and outlet of trout farms in Tonekabonʹs Dohezar river

The aim of the present study was to compare water quality parameters in inlet and outlet of two trout farms, and river water 500 m away from each farm in Tonekabonʹs Dohezar River. Dissolved oxygen, pH, water temperature, ammonium (NH4-N), nitrite (NO2-N), nitrate (NO3-N) and phosphate (PO4-P) were measured for 150 days in any mentioned sampling places. Water temperature solely showed insignificant difference in sampling places. The outflow water of farm 1 (8.77 mg/1) and farm 2 (8.17 mg/1) had the lowest dissolved oxygen. The rate of BOD5 showed a greatest value (4.85 mg/1) for outflow of farm 2 and it had a significant difference with other sampling area. Ammonium, nitrite, nitrate and phosphate revealed a significant difference in all sampling places (P<0.05). As a conclusion, trout farming with using water of Tonekabonʹs Dohezar river is still considered sustainable and did not impact on riverʹs ecosystem.