The Helgoland mud area in the German Bight is one of few sediment depocenters in the North Sea. It is therefore a suitable site to study long-term effects of anthropogenic pollution and/or natural environmental change. The high sedimentation rate in the area provides a high resolution for historical reconstructions. A five meter long core from the Helgoland mud area in the German Bight, North Sea, covering approximately the last 1000 years was investigated for benthic foraminifera. A pre- anthropogenic fauna, dominated by Nonion cf. depressulum, existed in the interval prior to the 19th century. It was intercepted by opportunistic species in periods with extremer conditions caused by lower or higher salinity levels. These opportunistic assemblages were found to be dominated by either Ammonia tepida or Elphidium excavatum. Since the beginning of the 19th century the fauna, indicating anthropogenic changes in river- runoff and nutrient fluxes, is dominated by Elphidium excavatum. During these last 200 years a much higher percentage of abnormal test deformation and indications for eutrophication caused by increasing organic matter content were found.