The Research Training Group “Baltic TRANSCOAST” investigates hydrological, biogeochemical and biological processes at the interface of a coastal peatland and the Baltic Sea at a site near Rostock. It is expected that the intensive exchange processes are modulated by sea level changes and occur above ground and below through submarine groundwater discharge. Water fluxes and solute transport through the coastal ecotone and along the coast, microbial processes, and the interaction of benthic animals and plants with their environment are the major topics of research.