بررسي بيوژيوشيمي محيطي عناصر ردياب در ماهيان حوزه آبريز رودخانه خرم آباد

The study of Environmental Biogeochemistry of trace elements in fishes of Khorramabad River Watershed

This study carried out in 2004 with the purpose of determining the source and quantity of pollution in the liyers of fishes of Khorramabad watershed by some pollutant elements. Fourteen environmental elements were distinguished in liver of cʹarʹious species of fishes that have been sampled by electro fishing method from 15 sites within this watershed by using atomic olrsorption spectrometer and flame photometer. The most important sampling (sites were) local mines, agricultural lands, mixed cones and urban/rural residential areas. The elements of lithium and silver were seen in none of the analyzed fish samples. The minimum concentration of trace elements in fish liver of the watershed belongs to vanadium and the maximumconcentration belongs to iron. High concentration of zinc in liver samples is because of the fishesʹ need to this minor nutritional element specially in early days of growth. Poor concentration of mercury and arsenic in fish her tissue is the result of agricultural poisons and drainage craters of marginal farms entering the surface waters of the study unit. The trace elements concentration in fish liver (is positively related) with the concentration of these elements in the find, water and sediments (Consumed) by fish, and with the rate of bioaccumulation.