Nature-based solutions: leveraging the coastal protective potential of seagrass in the Jade Bay region

Abstract

This study assesses the potential of seagrass meadows as a Nature-based Solution (NbS) to mitigate coastal risks in two locations within the southern German Wadden Sea: Jade Bay and the Outer Weser estuary. Using the unstructured-grid model framework SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model), coupled with wind wave and sediment transport modules, we simulated hydrodynamic processes over a two-year period (2019–2020), with a focus on the impact of an extreme weather event. We examined the hydrodynamic, wave, and sediment effects of seagrass presence versus absence under both typical and storm conditions and evaluated two restoration site scenarios. The results demonstrate that seagrass can substantially attenuate wave heights (up to 40 %) and bed shear stress (up to 70 %). Risk mapping further indicates that seagrass consistently reduces areas classified as high erosion risk and delays the onset of sediment resuspension during storms. These findings emphasize the protective function of seagrass and support its broader application as a scalable and adaptive strategy for enhancing coastal resilience under climate-driven pressures.