The Oder Estuary is a rural region at the German-Polish border. It has great ecological and recreational potential. The region suffers from economic and social problems and a steep gradient between West and East and between coastline and hinterland. Tourism development is one of the positive prospects – but it is depended on the quality of ecosystem services and is in conflict with other land uses (see www.ikzm-oder.de). The IÖW formulates future scenarios concerning the transformation processes in the Oder river basin up to the year 2020, which influence the nutrient immissions into the Oder. Agriculture and wastewater treatment are in the focus of the analysis. To assess the economic benefits of an improvement of ecosystem services, a choice experiment is carried out concernin the valuation of water quality in the Oder estuary. Furthermore the IÖW tests alternative policies to reduce nutrient emissionsn with respect to their cost-effectiveness.