Phosphorus and the Baltic Sea: Sustainable Management

Abstract

Worldwide, many aquatic systems are under anthropogenic induced pressure by elevated nutrient inputs. In particular, increased nitrogen and phosphorus usage have led to human‐induced eutrophication (including cyanobacterial blooms and hypoxia) of all kinds of water bodies. Associated pressures need to be described, and diminished, in order to reach a sustainable human usage of ecosystems. The Baltic Sea is a model system, as it is prone to Global Change, and is strongly influenced by human actions and shows recurrent cyanobacterial blooms and hypoxia. There have already been several actions to ameliorate these problems, e.g. by reducing the inflow of phosphorus. However, even the strongest possible reductions are currently not enough to restore the Baltic Sea. Coastal water bodies are still highly eutrophic, and the catchment area is affected by permanent runoff‐events from adjacent land. Furthermore, new approaches are needed to improve the efficiency of water treatment plants. On the other side, legislation is sometimes inefficient on a local scale. Such problems can only be solved in multidisciplinary approaches that include environmental, engineering and social sciences. Here, we present an overview of recent research with emphasis on phosphorus and its flows and controls into the Baltic Sea from the German catchment area. image