|Beschreibung:||The Wadden Sea is a coastal sea which is an ecologically important part of the shallow and sedimentary south-eastern North Sea. It is also a highly dynamic ecosystem. The main objective of this study is the analysis and quantification of the variability and development of the Wadden Sea ecosystem. Therefore, both biodynamics and morphodynamics in the northern Wadden Sea at the islands Sylt and Rømø have been taken into consideration on different time scales. Shorelines, surface sediments and megaripples were utilised as morphodynamic study targets while seagrass beds and mussel beds were taken as biodynamic parameters. Furthermore, the interactions that exist between these study objects were identified and the factors driving their development analysed. Data were collected by remote sensing of high-resolution aerial photographs with a Geographic Information System (GIS) as well as in ground-truth surveys and sampling campaigns. The five study parameters are affected by global climate change, which is among other things indicated in the Wadden Sea by increased hydrodynamics. However, there are also close interactions between them which can serve to amplify the effects of climate change. It is assumed that in the future the Wadden Sea faces substantial change brought about by erosion and the inundation of tidal flats together with the degradation of important habitats, as a consequence of global climate change. It can be expected that morphodynamic and biodynamic processes will accelerate and variability increase.