ECOLOGY OF THE LOWER RHONE AFTER 200 YEARS OF HUMAN INFLUENCE - A REVIEW

Embankments of the last century and contemporary channelization and development of urban and industrial areas along the Rhone Valley have greatly changed the river. The impacts of these on three biological descriptors of the hydrosystem (benthic invertebrates, fish communities and aquatic birds) have been studied. A reduction in the morphological diversity of the regulated hydrosystem has caused a reduction in biological diversity. This system has become a slow potamic system as a consequence of the more uniform environmental conditions: the benthic macroinvertebrate fauna has become eurytopic and pollution tolerant, with very localized potamic species; fish communities are dominated by limnophilic cyprinids; and water bird communities are limited by the absence of typical species of fluvial areas, such as terns.