Britain’s wild beaver populations are reducing the impacts of floods, cleaning river water, and boosting populations of fish, amphibians and water voles, a five-year study has concluded.
The aquatic mammals living on the River Otter in Devon have provided more benefits to people as well as their surrounding than the costs they caused, according to the study. Other wildlife, including fish, water voles, amphibians, and birds, have benefited from the presence of the beavers living on the river and creating new habitat.
However, they did cause some localized problems for several landowners, but these could be addressed successfully with ‘active management.’
The rodents were hunted to extinction in Britain 400 years ago and were not seen since, until five years ago, when a fenced trial was set up by the Devon Wildlife Truston the River Otter.
This population has been studied by scientists by the University of Exeter, to track their impact on the environment and farmland and see if they are safe to be set free from their fences. The Department for Environment, Food and Rural Affairs (Defra) is set to base its decision on whether to let beavers loose on their findings.
As the report was published, the Government said the trial had been extended until the end of August to assess the findings, which will help inform decisions on the future of the Devon beavers and their wider status in England.
The species has been given protected status in Scotland, where it returned through an official trial and illegal releases or escapes. England also has several fenced enclosures with beavers in to manage the landscape.
National polling, as part of the study, showed 86 percent of people support reintroductions and three quarters think beavers should be protected.
Beavers had been living wild on the Devon river for up to a decade when the trial began in 2015 but faced being re-homed in captivity after evidence emerged that they were successfully breeding.
Plans for a monitoring trial were put forward by Devon Wildlife Trust and were given the green light by Government agency Natural England, with the two-family groups allowed to remain on the water.
There are now at least eight pairs of beavers, occupying the main River Otter and the connected Tale, as well as some smaller tributaries.
According to the report, beavers have constructed six dams upstream of the village, which has measurably and significantly reduced peak flood flows through the community.
Evidence from another trial in north Devon, where beavers in an enclosure have built 13 dams and ponds, shows they also play a role in filtering soil, manure, slurry, and fertilizers from farmland.
Despite concerns that beaver dams might affect fish populations, the research found that in the pools created by damming the streams, there were 37 percent more fish than in comparable stretches of the river with no dams. Researchers also recorded trout leaping up and passing over beaver dams when river levels were high.