River-Coast-Sea: Water quality and climate change

Climate change affects not only coastal waters and the Baltic Sea directly but also the catchment areas of rivers discharging into the Baltic Sea. Measures must therefore be designed to address problems in all these areas. Diffuse nutrient loads from agriculture represent a key focal issue.

Climate change will affect river catchment areas as well as coastal areas and the Baltic Sea. Changes in nutrient loads through point and non-point sources in the upstream catchment areas impact the nutrient loads on rivers flowing into the Baltic Sea. Increased nutrient loads may worsen existing problems such as eutrophication, algae blooms, and anoxic zones in the Baltic Sea. Agriculture plays an important role in this context as it is responsible for a major share of nutrient loads on the catchment areas of the German Baltic coast. The coupling of agricultural, catchment area, coastal area and Baltic Sea models allows for a more powerful modelling system that is simultaneously able to capture the impacts of climate change and to quantify the impacts of land use change and other measures in the catchment areas. The modelling results can be used further, for example, in the implementation of the Water Framework Directive (WFD) to assess the necessary measures for the reduction of nutrient and other pollutant loads and their cost-efficiency. The first implementation measures for WFD (reference conditions, definition of good status) can be evaluated and the consequences for various uses along the coast (tourism, nature protection) can be assessed.