Description:
<jats:p>The development of the zoobenthic biocoenosis in the River Rhine in Germany during the 20th century has been documented in literature and by own investigations. The diversity of species and the structure of zoocoenosis are the elements of comparison. They show a drastic and continuing impoverishment in the benthic macroinvertebrate fauna throughout the 1950s, 1960s, and in the early 1970s. Since the raid-seventies a steady recovery of the communities has been observed. Causal dependencies between the development of the zoocoenosis and environmental factors like water pollution, river training, navigation and invasion of alien species (Neozoa) are discussed. Actions for improving the ecological situation are proposed.</jats:p>