Synthetic Aperture Radar (SAR) data have been included into an existing monitoring system to complement the classification of sediments, macrophytes, and mussels in the German Wadden Sea. Whereas the use of satellite-borne optical sensors in northern latitudes is strongly limited by clouds and haze, SAR data allow earth observation that is independent of cloud coverage and daytime. SAR data acquired at different radar bands (L, C, and X band, from ALOS PALSAR, ERS SAR and ENVISAT ASAR, and TerraSAR-X, respectively) have been used to analyse their potential for crude sediment classification on dry-fallen intertidal flats and for detecting benthic fauna such as blue mussel or oyster beds. In addition, we demonstrate that high-resolution SAR data can be used to detect residuals of historical land use, in intertidal areas that were lost to the sea during major storm surges in the 13th and 17th centuries.