Time and spatial variability in the concentrations of selected metals in water and bottom sediments of Pławniowice and Dzierżno Małe reservoirs (Poland).

The migration of metals and metalloids between bottom sediments and water and the other way round is a complex process. Understanding those mechanisms is essential for recognizing transformations taking place in water reservoir ecosystems. The objective behind the following study was to define time and spatial correlations in the changes in total concentrations of selected elements (Cr, Zn, Co, Mn, Cu, Ni, Pb, As, Ba, Sb, Sr and V) in waters and bottom sediments from two water reservoirs located in Upper Silesia (Poland), i.