Lake Kortowskie buoy – frequency: every 15 minutes (for open water period, 1m under water surface):
- water temperature, DO, conductivity, resistivity, total dissolved solids, pH, oxidation reduction potential, turbidity, Chl fluorescence, phycocyanin.
Meteorological station – since 1 to 15 minutes:
- wind speed and direction, air temperature, air pressure, radiation, humidity, rain amount.
Lake Kortowskie is located in the city of Olsztyn, in Masurian Lake District - Poland, and is one of the best investigated lake in Europe. The selective withdrawal of hypolimnetic water, the first lake restoration method in the world, was implemented in 1956 in this lake. Surface outflow was dammed, and a pipe was built at the bottom of the lake. Its inlet was located in the deepest, southern part of the lake, and its outlet – at the outflow from the water body. The restoration of Lake Kortowskie is continued, and multiyear studies supply very important data to analyze the changes in aquatic ecosystem. The surface of the lake is 89.7 ha and the maximum depth is 17.2 m. The catchment area of the lake is 35.5 km2: 48.4% - forest, 32.3% - agricultural land, 7.4% urban land, and 11.9% water.