SAR imagery of exposed mtertidal flats in the German Wadden Sea have been analyzed in order to retrieve location and distribution of oyster and mussel beds TerraSAR-X and Radarsat-2 images of five test areas along the German North Sea coast form the basis for the present investigation Multi-polarized multi-frequency and multi-temporal analyses of these data provided a valuable input for the detection of bivalve beds as much as for the routine monitoring of the mtertidal flats.