The fate of Cu, Zn and Cd after their entry into an unpolluted fresh water body was studied as a function of a condition of a natural phytoplankton community. In a field experiment, additives of metals entered into light and dark mesocosms twice to simulate effects of primary and repeated contamination. Over 31 clays, the reproduction of new generation of a phytoplankton as renewable source of the suspended particles capable to metal biosorption was higher in a light mesocosm. As a result the residual concentration of metals in water decreased faster and their content in the settled deposits was higher in a light mesocosm, than in a dark mesocosm. Efficiency of planktonic channel in deducing of metals from water with settling deposits (in the order of Cu > Zn > Cd) depends on intensity of a phytoplankton reproduction in the initial stage of water ecosystem contamination. (C) 2010 Elsevier B.V. All rights reserved.