Management of Wadden Sea Salt Marshes in the Context of Nature Conservation, Coastal Flooding and Erosion Risks: A Review

Salt marshes in the southern North Sea are part of the UNESCO World Heritage Site, Wadden Sea, the largest unbroken system of intertidal sand and mud flats in the world. They provide a very high nature value while significantly contributing to coastal flood and erosion risk management as a nature-based element of flood and erosion risk management systems for densely populated coastal areas. Climate change-induced sea-level rise is a significant concern: an integrated approach to salt marsh management adapted to the effects of climate change necessitates an understanding of the impact of different management strategies. This review commences with a description of the biogeomorphological conditions and processes in salt marshes for a better understanding of the natural dynamics and how they are influenced by management and climate change. Next, the impact of salt marshes on hydrodynamic processes and their role as nature-based elements of flood and erosion risk management is presented; management options and implementation methods are discussed and analysed concerning coastal flood management and nature conservation requirements. In conclusion, targeted salt marsh management needs to consider the initial conditions and the development aims of the specific site are integrated into a conceptual framework. Salt marshes have the potential to adapt to sea-level rise, thereby contributing to the long-term protection of coastal areas.