Biomonitoring studies have been carried out in three retention reservoirs located in the Opole Province (southern Poland): Turawa reservoir, Nysa reservoir and Otmuchow reservoir. The increases of concentrations of Mn, Fe, Cu, Zn, Cd and Pb in fresh water algae Spirogyra sp. and sea water Palmaria palmata (Linnaeus) Weber & Mohr, exposed in the analysed waters, were determined by the atomic absorption spectrometry method (AAS). Also the waters pH, conductivity and Mn and Fe concentrations were determined. The concentrations of Cu, Zn, Cd and Pb in the analysed waters were lower than the method limit of determination. The analyses were carried out during the period from June to July 2014. The differences between the increases of heavy metal concentrations in the samples of algae found along the coastline were indicated; they result from different distances from the pollution sources, such as sediments or drainage from the areas adjacent to the reservoirs. Better sorption characteristics of Palmaria palmata in comparison to Spirogyra sp. were indicated. An empirical interrelation was also tested, the application of which after modification may enable the quantitative assessment of waters pollution with heavy metals, based on the analysis of the concentration of the element in the algae thallus.