Ecological Rehabilitation of a Degraded Large River System – Considerations Based on Case Studies of Macrozoobenthos and Fish in the Lower Rhine and Its Catchment Area
✍ Scribed by Dietrich Neumann
- Publisher
- John Wiley and Sons
- Year
- 2002
- Tongue
- English
- Weight
- 81 KB
- Volume
- 87
- Category
- Article
- ISSN
- 1434-2944
No coin nor oath required. For personal study only.
✦ Synopsis
During the past two centuries, the meandering Lower Rhine has increasingly suffered under wastewater pollution, engineering projects for shipping traffic, and under settlements built on the former floodplain. However, in the past three decades the pollution has been remarkably reduced through the implementation of sewage treatment plants. This has resulted in a resettlement by both generalist and non-indigenous macrozoobenthos species (MZB) as well as by fish. Because the current species abundance pattern may change from year to year, it may be suggested that the river community (syn. biocoenosis) is continuously impacted by detrimental environmental conditions such as the residue from chemical spills, dispersal of dominating non-indigenous MZB species, strong fluctuations in the water load of the channel (correlated with long-term exposures of the river banks during low water levels), as well as by the lack of connected backwaters in floodplain areas. In 1987, the Rhine Action Programme focused on the reintroduction of long-distance migrating fish into the ecosystem of the River Rhine, in particular of Atlantic salmon. Migrating fish and their successful reproduction are important ecological signposts that can signalise an optimal rehabilitation of a river ecosystem. Thus, when studying the health of the ecosystem of a large river, the ecological state of salmon spawning grounds in the catchment area must also be taken into consideration. This paper focuses on current ecological problems and makes suggestions for future studies on the Lower Rhine and its tributaries.
Internat. Rev. Hydrobiol.