Ecosystem engineers: should beavers be introduced back into Welsh rivers?

Lucrezia Lozza

“When you start looking into some of the history books, you actually find that there is lots of evidence of beavers going back hundreds and hundreds of years and there are references in written literature, and in folklore in Wales,” said Alicia Leow-Dyke.

Alicia works at the Welsh Beaver Project, which aims to introduce beavers back into Wales for the first time in 400 years. The project wants to introduce 20 of the dam-building mammals into the Dyfi River in Powys.

One of the Welsh words for beaver is ‘afanc’, which in Welsh mythology is a type of river monster resembling a crocodile or giant beaver. The word ‘afanc’ can also be spotted in some place names, such as Llyn-yr-Afanc, which means ‘Beaver’s Pool’.

However, they were extensively hunted in Britain and Europe and their extinction in Wales dates back to the 15th century.

Since 2005, however, the Welsh Beaver Project has been investigating the feasibility of reintroducing beavers in specific and suitable areas of Wales in the future. With this in mind, the Welsh Beaver Project is working with Natural Resources Wales to obtain a licence for a first release of beavers into the Welsh wild.

“We’re trying to put the right information out there to demonstrate that beavers in the right place can be very suitable and beneficial to wildlife and people,” said Alicia Leow-Dyke.

As part of the licensing process of Natural Resources Wales, the Welsh Beaver Project will also undertake a public consultation on the matter, to see whether the population is in favour to the reintroduction of beavers in specific areas.

At the moment the Welsh Beaver Project is looking at the Dyfi catchment in west Wales as a potential location.

“At the same time we’re developing plans for a beaver enclosure on a Wildlife Trust reserve and we’re just waiting for some feedback from Natural Resources Wales,” said Alicia Leow-Dyke.

Not everyone is happy, however. Another example of a successful conservation project in Wales has been otters. The Cardiff Otter Project is a leading research centre on otter conservation and research, and it partners with several other institutions.

Dr Elizabeth Chadwick, Head of the Cardiff Otter Project, said that reintroduction of beavers were likely to face similar opposition, which is concern about the impact on fish in rivers.

“Some negative attitudes toward otter population recoveries include issues with otter predation on fish,” said Dr Elizabeth Chadwick, Head of the Cardiff Otter Project.

“Some people have used this as an argument against beavers, based on a misconception that beavers also eat fish – which is not the case. In fact, there is a lot of evidence that beaver introductions help boost fish populations.”

Advantages

The Welsh Beaver Project, however, are keen to point to a number of positive aspects of reintroducing beavers to Wales, particularly in relation to flooding.

Beavers are excellent ecosystem engineers: their dams slow the flow of rivers, so that when there is heavy rain it takes much longer to flow down and reach towns or villages.

In 2015 two family groups of Eurasian beavers were reintroduced in the River Otter catchment in south-east Devon as part of the River Otter Beaver Trial. Findings showed that peak flows of water in villages exposed to risks of flooding have significantly reduced thanks to the upstream beaver dams.

“There are many landowners who would like to see beavers back because of ecological and environmental benefits,” said Alicia Leow-Dyke. “They want the beavers to help to prevent the risk of flooding in the land if the dams are in the right places.”

There are other advantages to river biodiversity too.

“Their activities can improve the health of rivers and lochs, reduce flooding and the impacts of droughts, and contribute to carbon sequestration,” said Richard Bunting, a spokesperson from Rewilding Britain, a charity that looks at the restoration of nature and at reconnecting people with the natural world.

“They coppice and fell trees, letting light into woodlands, enabling plants to flourish and stimulating new tree growth.”

Beavers activities also boost the presence of other wild species: birds, small mammals, reptiles, amphibians have been seen increasing where beavers are present.

“This can encourage reptiles to move in, and water poles. Otters can all benefit from beavers increase in habitat,” said Alicia Leow-Dyke, Welsh Beaver Project Officer.

In the future, beavers in Welsh rivers might also be able to bring more tourism to the area, they say.

Intervention

However, finding a suitable habitat is a key factor for the reintroduction of species to prevent conflicts with humans.

“As well as detailed assessments of adequate and suitable habitat, any future reintroductions need to happen in full consultation with local communities,” said Richard Bunting. “These species have a role as ecosystem engineers and are essential to a flourishing natural environment”.

That can mean that some human intervention is required. For example, when “a small country lane experienced water encroachment as a result of an adjacent beaver dam, this was successfully resolved by occasional reduction of the height of the dam,” reads the final River Otter Beaver Trial report.

“Management costs are a tiny fraction of the value of the benefits of beaver reintroduction,” said Richard Brazier, Professor of Earth Surface Processes at the University of Exeter and Chair of River Otter Beaver Trial Science and Evidence Forum.

Beavers were reintroduced to Scotland in 2009 and now enjoy protected status there. Several beavers reintroduction trials have also proved successful in Europe, for example in Bavaria, Germany.

Perhaps Wales will be next, and the ‘afanc’ will no longer be relegated to Welsh myth but become a visible, and helpful, part of our lives once more.