Ecological rehabilitation of the Dutch part of the River Rhine with special attention to the fish

Abstract

The River Rhine has suffered severely from pollution and stream regulation over the last two centuries. Industrial effluents and municipal wastewater have imposed pollutant loads, and major engineering works for drainage and navigation have changed the ecological condition of the river. Only during the last three decades has the rehabilitation of the river system been a topic of concern. The present fish fauna is dominated by eurytopic cyprinids. Rheophilous species have declined in numbers, and anadromous fish have become scarce or extinct. Various forms of ecological rehabilitation in the Dutch Rhine are identified: floodplain development; optimization of migration routes with emphasis on the entrance of migrating species from the sea into the river; and restoration of spawning and nursery areas. Ecological restoration of the Rhine is an international effort. The present socio-economic functions of the river pose serious constraints on the feasibility of ecological targets. Copyright © 2001 John Wiley & Sons, Ltd.