Lake Balaton is the largest freshwater lake in Central Europe, with marshy meadows and extensive reed beds present along the shoreline. The lake supports large populations of plant and animal species which are important for maintaining the biological diversity of the Pannonian biogeographic region. During migration and wintering seasons, the Site is an important staging area for over 30,000 ducks, geese and coots, among them over 1% of the European wintering populations of several species. Balaton waters support approximately 2,000 species of algae and provide important spawning and nursery grounds for fish. The Site is the only South-East European refuge for the aquatic leaf beetle Macroplea mutica. Traditional human activities include fishing and reed harvesting, and the lake also constitutes a popular recreation area in Central Europe. There are 12 information centres and more than 20 nature trails around the lake. The main threats affecting the ecological character of the Site relate to unsustainable reed harvesting, the construction of sailing ports and fishing stages, the practice of motor sports and eutrophication caused by the use of fertilizers. The water quality of the lake has improved during the last 20 years as the rate of eutrophication has significantly declined. The Balaton Catchment Area Water Management Plan was approved in 2010.