Chlorococcalean algae from four lakes in the Slowinski National Park (Northern Poland)

We determined the variety of chlorococcalean algae in the total phytoplankton in four shallow lakes with different surface areas but having a similar average depth: Lebsko, Gardno, Dolgie Wielkie and Dolgie Male located in the Slowinski National Park, close to the Baltic Sea. Water samples for phytoplankton analyses were obtained from the surface zone during August 2001. A high number of chlorococcalean algae were found in all lakes. The taxonomic diversity was very high: 33 taxa in Lake Gardno, 42 in Lake Lebsko, 44 in Lake Dolgie Male and 46 in Lake Dolgie Wielkie were identified. The dominant genera were Scenedesmus and Desmodesmus. Both lakes, Lebsko and Gardno, are characterized by similar dominance structure compared to other lakes. It may be due to the higher water turbulence in those huge but shallow water ecosystems. There were clear differences between the lakes with respect to the quantitative presence of Chlorococcales and to the physico-chemical features of the water.