Assessment of heavy metal load in chub liver (Cyprinidae – Leuciscus cephalus) from the Nišava River (Serbia)

The Nišava River plays an important role as the source for both drinking water and agricultural irrigation dueto its hydrological and geomorphological characteristics as the largest river in the region of southeast Serbia.In this study we used the liver of the chub (Leiciscus cephalus) as a tool for biomonitoring heavy metalaccumulation along the river. Chub specimens were sampled from two localities (one at the border withBulgaria and a second in the city of Niš). Concentrations were estimated for six heavy metals (iron,cadmium, copper, zinc, lead and manganese) in chub liver. Low bioconcentration level was observed formost of the metals and the concentrations corresponded to the nominal concentration in livers of fishinhabiting metal unpolluted streams and rivers. However, cadmium concentration in the chub liver exceeded0.5 mg kg-1, a several hundred folds increase from nominal concentration indicating a potential toxicexposure of the fish and of the stream ecosystem to this heavy metal. Hepatosomatic indices were calculatedand tested for the impact of metal concentrations on liver size. A decrease of the hepatic index was observedin fish with higher cadmium concentration, suggesting a possible impact on the health of the chub populationin the Nišava River