Abstract:Submarine groundwater discharge (SGD) is known from many coastal areas around the globe.Although recognised to be an important transport pathway for pollutants and nutrientsfrom groundwater aquifers into coastal waters quantifying SGD is still difficult.Recent studies suggest SGD to contribute much more to total fresh water runoff andin particular to the exchange of solutes than previously assumed.A multidisciplinary approach was chosen for the EU project "Sub-GATE" for investigatingdifferent phenomena associated with SGD in the main target area Eckernförde Bay (WesternBaltic): Beside a qualitative, process-oriented understanding obtained by geological,biological, and geochemical field work discharge rates are to be quantified by isotopemethodes as well as by a groundwater supply model over the catchment area and diageneticmodelling.