Shallow lakes in North-east Germany: trophic situation and restoration programmes

Abstract

The research results of the Lake Project Mecklenburg-Western Pomerania allow an assessment of the trophic situation of the lakes of the north-eastern federal state of Germany. As a result, the trophic state of the majority of the lakes is higher than their potential of trophy, determined by the natural situation. About 65% of the investigated lakes of Mecklenburg–Western Pomerania are polymictic, predominantly formed during the last glacial epoch. Besides only a few lakes with a summer clearwater phase accompanied by high densities of macrophytes, these shallow lakes are more or less strongly eutrophicated and characterised by permanent massive phytoplankton blooms. Thus the sustained improvement of the water quality is necessary for most shallow lakes in Mecklenburg–Western Pomerania. Based on the research results of the Lake Project in Mecklenburg–Western Pomerania, a Redevelopment and Restoration Programme has been developed. To ensure sustained success, lake internal measures are only taken when the catchment area has been redeveloped or a redevelopment success becomes visible. The first measures of the programme already have been realised and further ones will be prepared.