How can we preserve diversity in our rivers?
Conservation actions fall short
- von Juliana Fischer
- 29.01.2025
Many conservation and restoration efforts are inadequate and achieve only limited success, according to an international study led by Professor Dr Peter Haase (University of Duisburg-Essen/Senckenberg). The research team systematically evaluated measures worldwide aimed at promoting biodiversity in rivers. The findings have now been published in the prestigious journal Nature Reviews Biology.
Rivers have always been vital resources, yet human interventions have severely harmed biodiversity in about 50 per cent of the world’s rivers. Wastewater, fertilisers, water extraction, and river straightening particularly affect densely populated regions in East Asia, Europe, North America, as well as arid and tropical areas. To reduce these pressures, legislations such as the Clean Water Act in the United States and the European Water Framework Directive were enacted. However, an international research team led by Professor Dr Peter Haase has scrutinised the effectiveness of these measures and reached a disappointing conclusion:
“In many places, conservation and restoration actions are insufficient to offset the pressures on our rivers,” reports Haase. “The loss of biodiversity in rivers is far greater than in terrestrial or marine ecosystems: 88 per cent of megafauna, such as river dolphins, turtles, and sturgeons, are threatened with extinction.” The research team evaluated a total of 7,195 projects in 26 regions worldwide regarding their effectiveness in preserving biodiversity in rivers. “The vast majority of these conservation actions achieved either no or only minor improvements in biodiversity. This lack of improvement does not necessarily indicate a failure of any individual action. Rather, it can be attributed in part to remaining unaddressed stressors driving biodiversity loss,” Haase summarises.
The study’s authors advocate for continuous monitoring of protective actions and the involvement of all relevant stakeholders. “A key to successful and effective protection of river biodiversity is what we call ‘co-production’ – the joint development of solutions by researchers, policymakers, potential Indigenous communities, and other local groups who directly benefit from river use,” explains Professor Dr Ralf Schäfer (University of Duisburg-Essen), a co-author of the study. A collaborative approach combines scientific and local knowledge, reduces conflicts, increases acceptance, and enables flexible, site-specific solutions to the complex challenges facing river ecosystems.
Further Information
Publication: Haase, P., Cortés-Guzmán, D., He, F. et al. Successes and failures of conservation actions to halt global river biodiversity loss. Nat. Rev. Biodivers. (2025). https://doi.org/10.1038/s44358-024-00012-x
Prof. Dr. Peter Haase,Senckenberg Forschungsinstitut und Naturmuseum Frankfurt/ Universität Duisburg-Essen, Leitung der Abteilung Fluss- und Auenökologie, peter.haase@senckenberg.de