The distribution of algae and zooplankton on two transects across reed and Polygonum stands was observed. The algal community in the Polygonum stand had a mosaic structure mainly comprised of green algae plus desmids and diatoms (Pediastrum simplex, Scenedesmus acutus, Closterium ehrenbergii), whereas blue-green algae (cyanobacteria) Microcystis aeruginosa and Woronichinia naegeliana dominated from the reed boundary towards open waters. Some species, such as Euchlanis dilatata, prefer to be associated with plants, while others, like Synchaeta kitina, are more numerous in open waters. On a windward shore, wind at a velocity of 4 ? 5 m s-1 caused a slow back current from 8 to 18 m h-1. Movements of water were sometimes linear, but at times they developed in two dimensions.