Conceptualizing the Baltic Sea ecosystem: an interdisciplinary tool for environmental decision making.

There is an increasing call for stronger interdisciplinary studies in the Baltic Sea to find solutions to the environmental and social problems associated with eutrophication. Cooperation between experts from the natural sciences, socioeconomics, and management is needed. One way to solve communication problems is to develop a broad conceptual model that comprehensively describes eutrophication and links causes, effects, and the multiple relationships of eutrophication in a visual way. In the present conceptual model, the eutrophication process is divided into i) causes, ii) primary effects, iii) secondary effects, and iv) socioeconomic responses. Each part is described and discussed separately, with links to the other levels and compartments. Possible pathways are shown through the model from natural science to human society, thus inducing management options. Examples of key publications where the causes and effects are observed and studied in the Baltic Sea are listed as examples, and their implications are discussed.