DNA can help clear our rivers of invasive mink

Cutting-edge science is set to help conservationists in their fight against one of Britain’s most damaging invasive species. A new project aims to eradicate North American mink from British waterways by using DNA analysis to identify how far the animals have travelled and pinpoint their routes to cut off re-entry to cleared areas. 

As mink have no natural predators, the Waterlife Recovery Trust has placed hundreds of traps across the east of England since 2020. Volunteers baited floating smart traps with an extract from mink anal glands to lure in the mustelids. Once a mink is caught in one of the traps, an alert is sent to one of the volunteers and the animal is humanely killed. Earlier this year, the group announced they had cleared East Anglia of the invasive creatures. 

Bill Amos, University of Cambridge professor of evolutionary genetics, has been involved in the project. “If you don’t know how far mink are moving, you don’t know the area you have to clear before you can be fairly sure they’re not coming back by immigration, so that’s where the genetics comes in,” he explained. “By analysing DNA samples taken from the caught mink, we can estimate the relatedness between them.” 

Professor Amos’s team also found that almost all family members were caught within about 15km of each other. Mink are voracious predators and will eat virtually anything they are big enough to catch. They and have been known to decimate seabird colonies. 

Additionally, Britain’s water vole population has plummeted by 97% since the 1970s because of the proliferation of the invasive species. The pioneering project has resulted in water vole numbers increasing in East Anglia. Professor Tony Martin, chairman of Waterlife Recovery Trust, told Shooting Times the recovery of wildlife in the eastern counties has been “remarkable” in the absence of the predator. 

“The marrying of cutting-edge science with good old-fashioned fieldcraft has yielded a unique opportunity to turn back the clock and remove invasive American mink from our countryside,” he said. 

“The pursuit of a mink-free GB has brought urban and rural communities together with a common purpose. It’s astonishing how quickly our native wildlife bounces back once mink have been vanquished. This is that rare thing – an environmental good-news story.”