Success at tackling invasive mink in Cambridgeshire

Mink numbers in Cambridgeshire have fallen dramatically thanks to a project aimed at removing the highly-damaging invasive, non-native species.

Back in 2021, the Countryside Regeneration Trust (CRT) and the Waterlife Recovery Trust teamed up with the shared goal of bringing life back to the waterways and wetlands of East Anglia through the removal of the American mink.

Four years later, the efforts are paying off in a big way, particularly in East Anglia and into Cambridgeshire, where mink numbers have dramatically dropped, and water vole numbers are growing once again.

Vince Lea, the CRT’s conservation officer, who has been involved in the project from the start, said: “The CRT is incredibly proud to have played an active role in removing mink from Britain, and this is now a realistic target.”

So far in 2025, only four mink have been caught in Cambridgeshire, a dramatic reduction from previous years. In 2021, 150 were trapped.

This drop signifies the success of the CRT’s carefully managed trapping network, which covers all the river catchments and the extensive area of fenland in the middle of the county.

While mink are still occasionally migrating into Cambridgeshire from surrounding counties, the eastern half of the county has largely become mink-free.

The CRT’s primary focus is protecting the water vole, which has faced population declines due to mink predation.

In the absence of mink, water vole populations are bouncing back across East Anglia.

“Water voles are still very rare there but, being rodents with high breeding rates, they can now start to expand. Water voles don’t tend to travel far during their lifetime, so it will take a few years to start to see them there, but I am sure they will come back. Trapping there will protect Cambridgeshire from the risk of reinvasion by mink,” Vince explained.

The project in Cambridgeshire is part of the UK’s largest attempt to eradicate a non-native species. Vince explained the success of this effort will not only ensure a future for water voles but will also improve conditions for nesting water birds such as common terns, moorhens, kingfishers, and black guillemots.

Initially, the project’s pilot focused on preventing mink from breeding in East Norfolk and Suffolk, with the CRT’s role in Cambridgeshire acting as a critical “buffer zone.”

In 2023, this effort paid off, with no evidence of mink breeding in the core area, suggesting that large-scale eradication is now feasible.