Long-term ecological studies in the North Sea and Wadden Sea supply key information on their pollution and reveal harmful influences. Furthermore, they enable an assessment of the ecological status of the sea and are thus an important tool for environmental policy decisions. The EU Water Framework Directive is a legal regulation aimed at achieving a good ecological status for all European coastal waters.

The extensive long-term ecological data series of the Alfred Wegener Institute for Polar and Marine Research (AWI) and the responsible scientists play a major role in the assessment of the ecological status of the North Sea. Parts of the time series have existed for 50 years. The animals, plants and microorganisms occurring at several stations in the North Sea are categorised on a regular basis. Physical parameters like water temperature and nutrient content complement the measurements and thus form a long-term series that is unparalleled even in an international comparison. Through these continuous investigations and by providing consulting services to the authorities, the AWI researchers help to monitor and improve the water and habitat quality of the North Sea.

Success has already been achieved in connection with the nutrient pollution of the North Sea. The nutrient loads of the big rivers Elbe, Weser, Ems and Rhine are still high, but political measures have led to their decline and to an improvement in water quality, which is documented by AWI measurements.