Major restoration work creates new habitats in the River Muick
The River Muick in the upper Dee catchment has benefitted from major restoration works this year, thanks to a project managed by the Dee District Salmon Fishery Board and River Dee Trust.
The project saw 40 large wood structures, made up of wind-blown trees, being installed in the Dee’s tributary.
The improvements were made over a five-kilometre stretch of the river from the outflow of Loch Muick down to the spruce plantation by the loch’s visitor centre, where trees were transported, manoeuvred and fixed into the river at carefully chosen locations in a bid to boost habitats for salmon.
Edwin Third, river operations manager for the Dee Fishery Board – who managed the £40,000 project funded by NatureScot’s Biodiversity Challenge Fund – said: “Salmon have a very complex life cycle, requiring different types of habitat at different stages.
“By adding large wood structures to the river, we can help to create these complex and diverse habitats for them.
“This restoration in the Muick is similar to the kind we undertook in the Gairn last year, where 110 wind-blown trees were secured in the river.”
The process is laborious, involving heavy machinery which transport the windblown trees over several miles to specific locations which are identified beforehand by a designer.
Edwin continued: “It’s a highly strategic process, because we want to get the biggest habitat benefit from the added trees.
“The designer walks the chosen stretches of the river and identifies the optimal sites – places where the river is trying to create some complexity by itself, where shingle has been deposited by the river and is beginning to make small islands and bars.
“The added wood then gives the river that material to accentuate those shingle bars and islands.
“In this way the trees are like the building blocks of the river structure – we just lend a hand by adding the wood.”
The process brings benefits for all aquatic species.
“Rivers like the Muick were once part of a wooded landscape, and trees in the river would have been a huge part of the habitat structure of the river,” said Edwin.
“Most of the Muick’s aquatic species would have evolved with that kind of river system in place, so putting them back in helps all the native wildlife in the river, interrupting and trapping vegetation and boosting aquatic insects.
“I’ve seen dippers standing on the wood we’ve added and jumping into the water to feed, otters love these kinds of structures too, as they provide such great entangled protection for them – the benefits are widespread.”
These latest large wood structures take the total installed in the catchment over the last three years to 104, made up of 400 trees, all of which have been firmly locked into the riverbed.
“They’re designed to stay in place,” said Edwin. “The ones in the Muick have been functioning well, and easily withstood the high spates and floods of October.”
As part of the same project Edwin and his team also built six ‘leaky dams’ across artificial drains close to the Muick, using natural materials such as logs, brush and tree cuttings.
He explained: “Manmade drains direct water into the river very quickly during storms, so adding a leaky dam to hold back the flow can help to reduce flood peaks, while simultaneously cleaning the water and creating additional wetland habitats. We’d like to build many more of these on a bigger scale.”
The effect of adding the trees will be measured by making a comparison of the river conditions before and after, but results from the Gairn and elsewhere in the catchment are already extremely promising.
Edwin said: “We did a baseline survey of the river before the trees went in, measuring what was there and what the various habitats were like, and we’ll monitor it again in a few years’ time to see how it’s changed.
“While we wouldn’t normally expect to see improvements in the river until a few years’ time, we’re already seeing strong signs of success, with salmon spawning right next to the new structures.
“We’ve seen the same immediate results in the Garbh Alt river further west in the catchment, and more recently, in the newly re-meandered Beltie burn near Torphins, which was especially heartening given how recently the works took place.
“To me all this spells huge success, and a clear sign that this type of restoration can make a difference to the overall health of the river and the catchment.”
Susan Cooksley, manager for the Dee Catchment Partnership, added: “A hugely difficult and challenging year for so many, 2020 has proved to be a positive year for the river Dee, thanks to the fantastic amount of restoration work that has gone ahead.
“The habitat restoration in the Muick is just one of a raft of projects across the catchment, from the planting of 87,000 more native trees and another 17km of agricultural buffer strips, to the restoration of the Beltie burn near Torphins.
“None of this would have happened without the unprecedented £830,000 of funding which came from a variety of sources including NatureScot’s Biodiversity Challenge Fund, the Scottish Rural Development Programme, Forestry Grant Schemes, the Cairngorms National Park Authority, the Woodland Trust, The Dee Trust and Board, and several private and corporate donations.
“It’s vital that these funding opportunities continue so we can build on all the great work done so far, and help to build a climate-resilient catchment that serves the needs of both people and nature.”