Rivers rank among some of the most threatened ecosystems in the world and are the focus of costly restoration programmes that cost billions to taxpayers.
Rivers in Europe are heavily fragmented by barriers such big dams, culverts, and weirs. These barriers provide essential services - drinking water, irrigation, or energy production, but barriers also block and fragment waterways, isolate habitats and weaken wildlife populations.
Under the motto "Let it Flow!" The EU Horizon 2020 project Adaptive Management of Barriers in European Rivers (AMBER) led by Swansea University, researchers took action to help reconnect hundreds of kilometres of river from barriers, improve fish migrationand develop tools to help manage European rivers in the future.
AMBER applied adaptive management to the operation of barriers in European rivers to achieve a more effective and efficient restoration of stream connectivity. To do this, AMBER developed tools, models and toolkits that will allow hydropower companies and river managers to maximize benefits and minimize ecological impacts. This will improve energy security, help protect jobs and boost European competitiveness, particularly in rural economies.
AMBER joined together 20 European partners including academics, conservation foundations (WWF, World Fish Migration Foundation), energy providers (EDF, Sydkraft Hydropower) and policy advisors (European Commission’s Joint Research Centre (JRC)). The team further engaged with key stakeholder institutions worldwide such as angling associations, environment ministries, fisheries agencies, river trusts and energy providers just to name a few.
AMBER provided the first comprehensive estimate of river fragmentation in Europe based on empirical and modelled barrier densities. A multidisciplinary team of researchers assembled 629,955 unique barrier records from 36 European countries and surveyed 2,715 km of 147 rivers to ground truth barrier densities. They also modelled the location and number of missing barriers.
Resource managers need to be able to quantify stream fragmentation, assess barrier impacts and benefits, and make better, informed decisions. The AMBER team developed a set of tools based on existing and future barriers based on what if scenarios. Tools included the:
AMBER Barrier Atlas – The most comprehensive overview of available information on barriers in Europe, showing more than 600,000 mapped obstacles.
AMBER Barrier Tracker - the first citizen science app to record river barriers. By using the app citizens can become scientists helping reconnect European rivers, track barriers, and learn about their impacts.
More tools are described in this policy brief. AMBER has received funding from the European Union's Horizon 2020 Research and Innovation Programme under Grant Agreement 689682.
Research stemming from AMBER found that there are at least 1.2 million in-stream barriers in Europe (mean density = 0.74 barriers/km), 68% of which are low-head (<2m) structures such as culverts, ramps and fords. Existing barrier records underestimate true barrier numbers by ~61% but this varies considerably between countries.
All rivers surveyed in Europe have barriers but relatively unfragmented rivers are still found in the Balkans, Scandinavia, the Baltic states, and parts of southern Europe. In the UK, 99% of river basins are fragmented by artificial barriers.
The project results fed directly into the European Green Deal. The new EU Biodiversity Strategy aims to reconnect at least 25,000 km of Europe’s rivers by 2030 and AMBER’s results contributed to this target. The AMBER Barrier Atlas and decision support tools will now be used to prioritise those rivers where gains in connectivity are most easily achieved and will bring about the greatest benefits.