Application of a biological tracer in transporting water volumes during eutrophication of Mondsee

The oligotrophic alpine lake Mondsee belonging to the system of eight lakes in the Salzkammergut region in Austria represented during our investigation the plankton distribution model in those parts of water areas that are situated in front of the estuaries of intensely eutrophicated mountain inflow torrents, such as Wangauer Ache and Fuschler Ache. Simultaneously with water sampling, measurements by drift floats were made to detect the water inflow direction and speed at several depths down to the bottom. The results have shown that horizontal as well as vertical plankton movement is an efficient biotracer for water flow parameters. Samples were collected in a "chessboard" way and also vertically at 5 m distances. Zoo-, phyto- and bacterioplankton were evaluated.