The River Dee Trust’s newly published report shows that the trees being placed in the Dee’s watercourses are having the intended effect of helping fish.
Several trees, including their root plates, are anchored into the riverbed and riverbanks to collectively make a ‘Large Wood Structure’ (LWS), which provides vital habitat for fish and other aquatic wildlife. After 3 years of monitoring, we can see that areas with these LWS have more juvenile fish than control areas which have no LWS.
The research has followed the installation of LWS on the River Muick, with the first surveys done in 2020, just before installation. The electrofishing surveys showed more juvenile fish (both salmon and trout) in areas with these structures in 2021 and 2022.
These trees affect waterflows, allowing the river to naturally create areas of spawning gravel for adult fish and nursery areas for juvenile fish, and creates scoured areas which provide pools. The structures provide vital cover for fish in times of flood and in drought, and to avoid predators. The structures also help trap nutrients which ultimately creates more natural food in the area for aquatic life.
Trust Biologist, Al Reeve said “We have seen an immediate increase of fish where LWS have been installed. The Muick is habitat-poor and by providing the structure and shelter for juveniles to survive will lead to increased fish survival and, ultimately, more fish coming back to spawn in the Muick”.
The Dee Fishery Board and Trust have so far installed 158 LWS into the Dee’s tributaries. This year, a further 97 structures are going into the Clunie and its tributaries as part of a project supported by Scottish Government’s Nature Restoration Fund, which is managed by NatureScot.
The Trust’s survey report can be viewed here https://riverdee.org.uk/wp-content/uploads/2023/02/Muick-Large-Woody-Structures-2020-2022-3.pdf and this monitoring is set to continue.
If you have any queries, then please get in touch with the River Dee Team at info@riverdee.org