Heavy metals assessment in water and sediment of Gorgan Bay before and after rearing wild common carp(Cyprinus carpio) in pen culture (khozeini Canal)

This research was carried out to investigate heavy metals in water and sediment in the east of Khuzini Channel before and after fish breeding in pen culture in Gorgan Gulf in 2013-2014 .For this purpose, three active fish farm stations in the pens, the sturgeon farming station and the eastern station were selected at a distance of 500 meters from the eastern part of the pens. Water and sediment sampling was carried out in March 2013 and once at the end of the breeding period in June 2014.The measured metals in the viscose included Ni, Pb, Fe, Cd, Cr, Hg, Zn, As. using atomic absorption spectrophotometric method. The results showed that the range of Pb, Zn and Cr at the beginning of the breeding season in the month of March was 6.72-7.78 and 1.282-1.430 and 4.554-8.18 respectively, and the highest amount of heavy metals was related to Fe include 130 ppb in pen culture site. in June 2014, the range of Pb, Zn and Cr was 0.00403-0.0 0462 and 0.0121- 0.0028 and 0.00465 - 0-00546 mg / kg respectively. The maximum range was belong to Fe (20 ppb) at the pen. The lowest amount was belong to Hg less than 1 (ppb) at each stations. The values obtained in the study comparing with the WHO standard values showed, about the water, The level of pollution of Zn, Cr and Pb was less than global standard and related to pollution of sediment except Fe, was less then global standard too.