Biomarkers responses in Salmo salar exposed to multicomponent metal mixtures

Pollution of freshwater from industrial, domestic and agriculture sources is one of the major factors responsible for the decline of Atlantic salmon (Salmo salar) populations in Europe. Biomarkers responses (bioaccumulation, glucose content, cytogenetic and behavioral endpoints) elicited by the most common metal contaminants at Maximum-Permissible-Concentrations (MPC: Zn – 0.1, Cu – 0.01, Ni – 0.01, Cr – 0.01, Pb – 0.005 and Cd – 0.005 mg/L) accepted for the inland waters in EU was assessed in fish after 4 h, 1, 2, 4, 7, 14 or 28 days of exposure. Experimental studies were performed using whole mixture approach and by reducing environmentally realistic concentration of single metal in the mixture by 10-times (represents background exposure in the aquatic environment). Bioaccumulation of metals was assessed in gills, liver, kidneys and muscle tissues. In the most of the investigated tissues, steady-state metals concentrations were reached within 14 days. All metals have attained steady-state in muscle. Metal mixture at MPC and 10-fold reduction of single metal in the mixtures significantly affected cytogenetic, behavioral endpoints, blood glucose content and bioaccumulation of several metals in analysed tissues of fish. Therefore, discharges of metals at MPC into the aquatic environment can lead to health problems of juvenile S. salar.