Skallingen

Dune formation on Skallingen

In the northernmost part of the Wadden Sea, on the Skallingen barrier-spit (Denmark), lies one of the few places on a Wadden Sea island where natural processes can proceed undisturbed. As the peninsula is uninhabited, coastal protection measures were largely abandoned in the 1990’s to allow the natural washover processes to unfold again. Only a small area south of Skallingen remained modified, following a clearance of World War II mines. There, two old groynes were retained for political, historical, and management reasons, reflecting the limited legacy of past coastal interventions.   

Today, during storm surges, waves and wind transport material from the beach and foreshore area into the hinterland, allowing new dune ridges and salt marshes to form. These processes support a mosaic of early successional habitats, where pioneer vegetation such as Marram grass helps stabilise dunes and initiate ecosystem development. This also enables the local accumulation of sediments and thus vertical growth, which is increasingly important in times of accelerating sea-level rise. The dynamic interface between dunes, salt marshes, and tidal flats provides important feeding and resting grounds for migratory birds, making the area a valuable biodiversity hotspot within an otherwise highly dynamic coastal environment.  

However, due to the lack of coastal protection, coastal erosion and shoreline retreat on the western side of the peninsula continues. Consequently, the Skallingen peninsula is effectively ‘migrating’ to the northeast, illustrating a landscape that adapts through movement and reshaping rather than fixed stabilization. 

Why is it a NbS (with regards to IUCN Definition)? 

Restored natural dynamics (also conforms with Climate Change Adaptation Strategy for the Wadden Sea) which increases biodiversity and enables vertical growth thereby adapting to sea-level rise. 

Purpose of the NbS: 

Increasing natural dynamics: vertical growth and the development of dunes and salt marshes, thereby protecting the Wadden Sea and the hinterland.  

Further information on this NbS: 

Aagaard, T., & Kroon, A. (2019). Decadal behaviour of a washover fan, Skallingen Denmark. Earth Surface Processes and Landforms, 44(9), 1755-1768. 

Fröhlich, J., & Rösner, H. U. (2015). Klimaanpassung an weichen Küsten: Fallbeispiele aus Europa und den USA für das Schleswig-Holsteinische Wattenmeer. WWF Deutschland, p. 25 ff. 

Oost, A. P., Hoekstra, P., Wiersma, A., Flemming, B., Lammerts, E. J., Pejrup, M., ... & Wang, Z. B. (2012). Barrier island management: Lessons from the past and directions for the future. Ocean & coastal management, 68, 18-38.