More than one million instream barriers are impeding European rivers’ biodiversity
European rivers are fragmented by almost 60 per cent more barriers than previously thought, according to new research published by an international team including experts from the University of Southampton.
The study, involving scientists from Southampton’s International Centre for Ecohydraulics Research (ICER) , found that the flow of rivers and movement of animals is being impeded by more than 1.2 million instream barriers.
Many of these obstructions are small barriers – including weirs, culverts and fords less than 2m high – that have historically been overlooked.
Professor Paul Kemp , of the Water and Environmental Engineering Research Group , says: “European rivers have suffered from a long-historic legacy of many hundreds of years of river engineering for agriculture, flood prevention, navigation, electricity generation and water supply.
“This has resulted in a very high density of small barriers that have degraded the ecological status of our rivers so that many fail to meet the basic standards of the EU Water Framework Directive.”
The international research team have published their findings in Nature .
This study is one of the main outputs of the EU Horizon 2020 project Adaptive Management of Barriers in European Rivers (AMBER) which, for the past four years, has been mapping river barriers across Europe to provide the first pan-European assessment of river fragmentation.
Dr Jim Kerr , Research Fellow for the AMBER Project, says: “Our rapid barrier assessment tool provides critical data that feeds into methods to prioritise restoration actions, such as dam or weir removal, by the most cost-effective means while providing the greatest gains for regeneration of lost biodiversity.”
The results of AMBER have already reached policy makers and fed directly into the 2030 Biodiversity Strategy, helping to set a clear target of reconnecting at least 25,000 km of Europe’s rivers by 2030.