The Baltic Sea coast of Mecklenburg-Vorpommern is characterized by numerous former coastal fens along its bays, inlets and estuaries. The originally approx. 40,000 hectares of coastal flooded peatlands are now mostly diked and drained. Restoration or renaturation has only been successful in individual cases, with the result that the condition of more than 60% of these fens is still deteriorating. As part of the project, predominantly agriculturally used peatland areas in 12 coastal polders are to be restored. This could reduce climate- damaging emissions by 15,000 - 24,500 tons of CO2 eq. per year on the planned total area of 850 hectares. Near mean water level, where the altitude allows, the sink function of the areas as carbon reservoirs is to be restored through the re-establishment of peat-forming plants. In addition to the climate protection effect, important ecosystem services such as peatland growth, flood protection, nutrient retention, groundwater enrichment and biodiversity growth are achieved or initiated. As part of the IOW's accompanying scientific research, nitrogen emissions and turnover are systematically recorded and quantified at selected sites. For this purpose, nutrient concentrations and denitrification rates in the soil are determined. The intersection of the rate measurements with other environmental variables will provide information on the regulation of processes in the various polders in close cooperation with the Baltic Sea Foundation and the University of Greifswald. At the end of the project, comparative multi-year observations will allow statements to be made about the real emission reductions through rewetting on coastal fens, and open up different strategies for peatland restoration and their climate impact.