Two beavers were released on Monday to join the existing wild colony living on the River Otter in Devon.

In January 2014, retired environmental scientist Tom Buckley captured footage of one of group of beavers living on the River Otter after his suspicions were aroused by damaged to trees similar to marks he had seen created by beavers in Canada. The discovery of the first wild beaver colony in Britain in over 500 years caused concern for government officials, who first planned to remove them, then wanted to check they were free from tapeworms before finally agreeing to let them stay in March 2015. The beavers enjoyed a huge amount of public support, including from the farmer on whose land they were first filmed.

Devon Wild Life Trust also gained permission to carry out a five year beaver reintroduction trial. In a move to boost the beaver’s gene pool, two more animals were released in a secret location near the river on Monday. An adult female and adult male from two captive beaver trials bing conducted in Devon were released at the site in East Devon.

Though locals backed the beavers, and England’s only wild colony is expected to generate a significant amount of eco-tourism, in its response to a government consultation in January 2015, the NFU said the union is “Opposed generally to species re-introduction programmes,” noting “Resources can be used more effectively to improve existing biodiversity” and stating that “The NFU specifically opposes the re-introduction of the European Beaver because of concerns about the damage to farmland and farming operations caused by their physical activities and the risks of them spreading disease.”

Commenting on the release, Devon Wildlife Trust’s Peter Burgess said, “There are already 12 beavers known to be living on the River Otter. Our DNA analysis has shown that these animals are closely related to one another. The genetic diversity of the beavers needed to be increased to ensure that we have a healthy population.”

“This pair of beavers may move down river to mix and then breed with the existing population very soon, or they may decide to stay-put, pair up and breed. Then it will be their offspring which mix and mate with the other beavers. Either way the outcome will be the same; the genetic diversity of beavers living wild in East Devon will have been enriched. That is our goal.”

The loss of beavers coincided with a loss of meres and bogs in which they made their homes. The Wildlife Trust said the return of this ‘keystone’ species will provide a boost for river ecology, possibly alleviating flooding downstream of their habitat, increasing water retention, easing the impact of periods of low flow and the Trust even said the presence of beavers has been linked to water purification and lower diffuse pollution.

As part of the trial, which has been sanctioned by Natural England, the two new beavers will be monitored using cameras to gain an insight into their behaviour.