Chloride, phosphate, sulphate, ammonia, hydrogen carbonate concentrations, the redox potential Eh and the pH of bottom sediments were determined. The spatial distribution and profiles of selected species are presented. These parameters showed great variability (e.g. potential redox values ranged from -358 to 223 mV), which depended mainly on the penetration of underground waters and station location, and but only to an insignificant extent on the bottom type. Higher redox potentials were recorded for samples with low PO43-, NH4+, HCO3- and Cl- concentrations and with high SO42- concentrations. The relationship between redox potential and the concentration of species originating from the oxidation of organic matter, e.g. PO43-, NH4+ and HCO3-, was found.