Genetics ‘a new tool to help boost water vole conservation’

Genetics could be used as a new tool to help boost water vole conservation in the UK, after scientists analysed the DNA of one of the country’s most threatened mammals.

Researchers at the Wellcome Sanger Institute have sequenced the genome – a complete set of genetic instructions – of the European water vole (Arvicola amphibius), a semi-aquatic rodent under serious threat from habitat loss and predation by the American mink.

Details of the genome, generated in collaboration with animal conservation charity the Wildwood Trust, have been published through Wellcome Open Research and are available to researchers and conservationists looking to better manage reintroduction efforts.

Professor Mark Blaxter, of the Wellcome Sanger Institute, said: “The European water vole is a prime example of a British species whose genetic diversity we’re in danger of losing before we’ve had the chance to fully record it.

“This high-quality Arvicola amphibius reference genome will allow us to do that, as well as support ongoing conservation efforts to preserve existing populations and reintroduce new ones in a way that ensures these populations are genetically robust.”

Water voles are considered endangered in the UK, after their population declined from 7.3 million in 1990 to an estimated 132,000 in 2018.

The creatures owe their genetic diversity to voles from Iberia and Eastern Europe, which arrived in Britain after the end of the last Ice Age more than 10,000 years ago.

But experts say they do not know how much diversity has been lost as a result of the recent population crash.

Hazel Ryan, senior conservation officer at the Wildwood Trust, said: “Water voles are amazing animals and we don’t fully understand what ecosystems lose without them.

“They are industrious habitat managers, almost like miniature beavers in the way they fell stems, make burrows and alter the landscape.

“We suspect that some water vole populations have become inbred in recent decades owing to shrinking numbers and the fragmentation of populations through habitat loss.”

To generate the genome, the researchers analysed blood samples from a live male water vole.

It is hoped that the the so-called reference genome could be used to assess water vole population genetics.

Ms Ryan said: “The reference genome offers us a way to better understand genetic diversity for reintroductions and consider mixing individuals to ensure populations have the best chance to thrive.”

Professor Rob Ogden, director of conservation science at the University of Edinburgh, added: “Understanding the genetic diversity and structure of water vole populations is an important aspect of their conservation in the UK, and is central to international guidelines on the movement of wildlife for conservation management.

“The release of the water vole genome provides a comprehensive set of genetic tools to support the future sustainability of the species in the UK.”