Barriers and obstructions in freshwater rivers
Scotland’s river network contains many barriers to fish migration, both natural and man-made.
MS Maps NMPi has two layers:
- Obstacles to Fish Passage (SEPA WMS)
- Impact of Impassable Barriers on River Connectivity – this is a sub-set of layer (1).
Layer (1) is maintained by the Scottish Environment Protection Agency and represents the natural and artificial obstacles to the migration of fish, mainly salmonids, in Scotland. The data originate from information collated since the 1980s by Marine Scotland while identifying the distribution of salmon in Scottish rivers.
Layer (2) is based on work undertaken by University of Aberdeen, Marine Scotland, James Hutton Institute and Leibniz Institute of Freshwater Ecology and Inland Fisheries to assess the impact of impassable man-made barriers on juvenile Atlantic salmon production and provide a tool for prioritising barrier removal, where red indicates a high priority for management and green indicates low priority. Improving river connectivity increases the amount of available salmon habitat.