XVI International Botanical Congess

In the last years under the influence of anthropogenic factors essential modifications of the taxonomic and quantitative structure of planktonic algae from the main aquatic ecosystems of Moldova were recorded.The investigations on the phytoplankton of Nistru and Prut rivers, of accumulation lakes Cuciurgan and Dubasari during 1951-1998 were emphasized the existence of 867 taxons, of which 448 come from the river ecosystems and 808 from the lake ecosystems.The composition of the phytoplankton of the studied ecosystems have reduced in the last years (1991-1998) with 50-60% as a result of hydrologic regimen modification, of industrial pollution, of progressive eutrophysation. Simultaneously, essential modifications in quantitative development of the phytoplankton were take place.