Physico-chemical and bacteriological studies of trout Farms along the Haraz River

Objective: This study was conducted to characterize extensive rainbow trout (Oncorhynchus mykiss) farm effluents, including physicalchemical and bacteriological compositions and river water quality changes. Method & Materials: In this study three fish farms with different capacities were selected along the Haraz River. These farms are namely A, B and C. The water samples were taken at inlet and outlet of fish farms. Parameters at inlet waters and effluents were included temperature, total suspended solids, pH (WTW-320, Germany), Total alkalinity, total hardness and Cl- (Titrimetric method), TDS and EC (HACH, USA), DO and BOD5 (Iodometery method), ammonia and nitrate, phosphate Spectrophotometer (HITACHI, UV-2000, Japan) and bacteria. Analyses were performed according to Standard Methods. Results & Conclusion: Results of this study showed that PO4-3 – P (p<0.011), NO2--N (p<0.009) and NH4+ (p<0.027) were increased significantly from Farm A to Farm B and from Farm B to Farm C only for TP (p<0.019), NO2--N (p<0.019), TDS (p<0.001), EC (p<0.001). Daily net mass flow for annual fish production was computed. DO mass flow for each farm decreased from inlet to outlet but for BOD5 increased. The results suggested that suitable distance between farms are different and depends on the fish populations and farms activities, dilution and self-purification capacities of the water body. Furthermore, suitable distance was also affected by physical-chemical and bacteriological characteristics of outlet of upstream

کلیدواژه ها:

Rainbow Trout farm ، Effluent ، Environmental impact ، Haraz River ، Iran