---

Kurdistan province is one of the most important provinces in Iran in terms of surface and underground waters, and the Garan resevior (Marivan) has important rules in aquaculture and fisheries activities. For this purpose, the present study was carried out including a survey of 22 physico-chemical parameters at four sites of Garan reservoir from July 2017 to August 2018. Results showed that the mean value of water temperature 11.13 ± 6.7 °C and the Dissolved Oxygen (DO) concentration was 8.44 and 3.87 mg/l for surface and deep layers respectively. Based on the results, was shown that the Thermocline and oxycline start from June and they vanish in December as well as. Mean of pH value 7.99 and secchi disc depth was high (2.3 m) relatively. Also the mean value of alkalinity, Biochemical Oxygen Demand (BOD₅), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS), Total Dissolved Solids (TDS) and electro conductivity 138.59, 1.32, 25.02, 0.047, 156.91 mg/l and 242.18 (µmhos/cm) respectively. Also mean of nutrients were within desirable limits. In general, although seasonal and spatial variations were observed in some parameters, but according to the results of physico-chemical characteristics, the Garan reservoir could be considering suitable for standard pattern of aquaculture activities.
 

---

This study was carried out to determine the effect of raibow trout cage culture on the abiotic factors of water in the Abbas Abad area, southern basin of the Caspian Sea. For this purpose, water samples were collected at distances of 5, 50, 100 and 1000 m from the cage culture during December 2014 to August 2015. Based on the results, it was shown that the mean value of water temperature for surface layer varied between 12.2 and 30.16 °C from December to August. The highest and lowest mean value of salinity obtained in August (11.26 g/l) and April (10.66 g/l) respectively. The range of pH value changes (8.36-8.83) was as small as the rate of electro conductivity variations (18.11-19.07 µs/cm). The highest concentration of dissolved oxygen was observed in December at 1000 m station (9.23 mg/l) and the lowest was seen in April at 5 m station (7.27 mg/l). Also the mean values of Total Dissolved Solids, Turbidity, Nitrite, Nitrate, ammonium, Total Nitrogen, Phosphate and Total Phosphorus was obtained 9.59 (g/l), 5.55 (NTU), 3.67, 133.45, 92.6, 929.72, 21.63, 37.73 (µg/l) respectively. The results of abiotic factors of water showed that most of the measured parameters had significant differences only among different sampling periods (p<0.05) whilst, for some factors such as dissolved oxygen, ion ammonium and phosphate, there were significant differences between different stations (The effect of distance from the cage) at each sampling period as well as (p<0.05). It seems that the cage culture of rainbow trout in the Abbas Abad area had only a minor impact on measured factors probably due to low stocking density, short-term of fish farm and high current velocity.