Between September 1992 and September 1966, a subtidal sand bar in the main tidal inlet of Sylt-Römö Bight in the northern Wadden Sea was sampled for macrobenthos and sediment composition twice a year in spring and autumn. During each sampling date, six replicate box cores were collected from each of 4 subsites, sieved trough 1 mm meshes and preserved in buffered formaldehyde solution. Individuals were determined to species level and counted, abundance is given as individuals per core (0.02 m²).