Researchers from the Inverness College UHI Rivers and Lochs Institute probe will contribute to European collaborative AMBER (Adaptive Management and Barriers in European Rivers) project
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Analysis of the fragmentation of Scottish rivers by researchers from the Inverness College UHI Rivers and Lochs Institute (RLI) is contributing to an important study.
The work – part of the European collaborative AMBER (Adaptive Management and Barriers in European Rivers) project – shows European rivers are impacted by more than 1.2 million in-stream barriers and fragmentation in all countries is much higher than expected.
Professor Eric Verspoor, of the RLI, said: “This study provides a stark pan-European account of the massive numbers of barriers in Europe’s rivers, including many in Scotland, whose negative impacts on riverine ecology we are only now starting to fully appreciate and mitigate.”
The study found that even Scotland’s relatively pristine river ecosystems are more fragmented by barriers such as dams and weirs than previously believed. Although all major barriers are captured by the existing database curated by the Scottish Environmental Protection Agency, there are still areas within Scotland where knowledge is incomplete, as highlighted by the study.
Barriers, in many cases, can be expected to have significant negative impacts on their fish communities, and especially on the abundance of migratory species like the Atlantic salmon, sea trout and eels.
They have historically been constructed to provide energy, water, fishing, access and leisure opportunities, but can also pose potential flood hazards and change freshwater habitats, including impeding or blocking the migration of fish, and changing natural patterns of biodiversity, posing challenges for ecologically sound, sustainable river management.
As part of the broader AMBER project, the RLI team worked in partnership with the Ness District Salmon Fisheries Board and Scottish and Southern Energy to contribute to addressing this challenge, extending work conducted as part of the Upper Garry Salmon Restoration Project on the River Ness.
This focused on using new ways of monitoring the impacts of river fragmentation on river biodiversity arising from the presence of hydro dams and Caledonian Canal water diversion weirs and its tributaries, combining aerial drone photography and biodiversity assessments based on environmental DNA (eDNA).
Dr Lucio Marcello, of the RLI, said: “By more clearly understanding barrier impacts on river ecosystems, we can identify possible ways to deal with existing barrier installations.”
The RLI researchers worked with researchers across Europe to collate regional, national, and global datasets to assess the number of individual barriers on rivers to create the first ever comprehensive pan-European barrier inventory.
