Survey of physicochemical properties and nutrients in surface waters of the southern Caspian Sea- Seasangan

This study was conducted in the southern Caspian Sea region – Seasangan, to study physicochemical properties of surface waters (salinity, chemical productivity, alkalinity, pH, total suspended solid and dissolved oxygen). In this study, nutrients (phosphate, total phosphorus, nitrate, nitrite and silicate) in surface waters was also investigated. Sampling was done in 12 stations in four vertical transects on autumn 2012. The results indicated Salinity range of 11.16- 11.30 g/kg, chemical productivity of 17.75- 18.27 mS/cm, dissolved oxygen of 8.25- 8.42 mg/lit, alkalinity of 187.5- 200 mg/lit as CaCO3, total suspended solid of 8- 12 mg/lit and pH range of 8.25- 8.42, respectivly. The concentrations of phosphate ranging from nd to 0.01 mg/lit, nitrite ( non detectable), total phosphours of 0.001 to 0.005 mg/lit, silicate of 0.064 to 0.221 mg/lit and nitrate of 0.011 to 0.071 mg/lit. There were not significant differences in nutrient levels, alkalinity and total suspended solid in transects (P> 0.05). The results showed that the nutrient levels in the Seasangan surface waters were lower compared to other regions in the southwest and southeast regions of the Caspian Sea.