The presence of heavy metals in water and the muscle tissue of grayling (Thymallus thymallus) of the Una River : Присуство тешких метала у води и мишићном ткиву липљена (Thymallus thymallus) из ријеке Уне

Heavy metals belong to a group of substances, which, after reaching a natural habitat, can manifest various negative effects. This paper analyses heavy metals (Cu, Cd, and Pb) in the Una river and fish samples, whereby individuals of grayling (Thymallus thymallus) were used for analysis. The samples were taken at three locations at the Una river: Ripac, Hatinac, and Grmusa. Alongside with the examination of the content of heavy metals, quality of water was tracked, including the following parameters: temperature, pH, electrical conductivity, dissolved oxygen, suspended matter, BPK5, KPK – Cr, total nitrogen – N, total phosphorus P, sulphates, chlorides, nitrites – NO2, nitrates – NO3, fluoride, and heavy metals (Cu, Cd, and Pb). Besides the content of heavy metals, proteins, fats, water, carbohydrates, and mineral matter were found in the grayling fillets. Amount of heavy metals (Pb, Cu, and Cd) were under maximum allowed concentration (MAC).             Key words: heavy metals, water, fish.