Prostyr is a complex of near-natural sedge and reed fen mires with black alder groves and scrub formations along the banks and floodplain meadows of the rivers Pripyat, Prostyr and Styr. Such eutrophic floodplain mires are typical of the Belarusian Polesie area, but they have become rare as a result of heavy drainage since the 1960s and have practically disappeared in Central Europe. The Site is a breeding ground for the globally vulnerable aquatic warbler Acrocephalus paludicola and is generally one of the most important breeding and stopover sites in Belarus for migrating waterbirds. The vast natural floodplain meadows and mires also provide important spawning grounds and sources of food for fish. Small-scale economic activities take place within the Site, mainly associated with manual haymaking. Recreational activities are limited to amateur fishing and water tourism along the rivers. The existing network of drainage canals within the Site and in the surrounding areas continues to drain the fen mires. The disruption of the natural water regime as well as changes in traditional economic activities have led to the transformation of natural fen mires, encroachment of shrubs on open mires and meadows, disappearance of some rare plants and animals and also fires.