Four Years On: A Look at the CRT’s Mink Eradication Efforts in Cambridgeshire

In 2021, the CRT teamed up with the Waterlife Recovery Trust to take on a monumental task—creating a mink-free Britain.  

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 voles are thriving once again.  

This success is a result of years of hard work, dedication, and a deep commitment to restoring Britain’s native ecosystems. 

The Progress So Far: Mink Numbers Plummet 

So far in 2025, only four mink have been caught in Cambridgeshire, a dramatic reduction from previous years. 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. 

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.” 

While mink are still occasionally migrating into Cambridgeshire from surrounding counties, the eastern half of the county has largely become mink-free. By 2023 the ‘pilot project’ of Waterlife Recovery Trust East proved successful, with no signs of mink breeding in the core areas of East Norfolk and Suffolk, and that has remained the case throughout 2024 and so far into 2025, proving that large-scale eradication is possible with a coordinated effort. 

Vince Lea checks out a mink trap that has been activated on the River Great Ouse in Cambridgeshire in 2022.

Vince Lea and Emily Coleman install camera and water vole excluder on mink raft

A Win for Water Voles 

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. Vince is optimistic about the future of water voles, saying, “Our neighbouring counties to the west, Northamptonshire and Bedfordshire, have only just come into the project and had large mink populations when Waterlife Recovery began there. 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.” 

The Largest Mink Eradication Initiative 

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. 

Expanding the Trapping Network 

The CRT’s mink trapping efforts have expanded beyond Cambridgeshire.  

New trapping operations have been set up at the CRT’s Bere Marsh Farm in Dorset and Pierrepont Farm by the Frensham Flyfishers, which is part of a much larger effort across South-east England.. The ongoing data collection from these efforts continues to provide valuable insights into the project’s success and the progress of mink eradication. 

“We are proud to be supporting the expansion of mink trapping across Britain,” said Vince, “and we are determined to reach the point where trapping is no longer necessary.” 

Mink Reduction Over the Years in Cambridgeshire

• 2020: 50 mink trapped (no coordinated trapping) 

• 2021: 150 mink trapped (first year of full trap network) 

• 2022: 56 mink trapped 

• 2023: 27 mink trapped (one breeding female found) 

• 2024: 18 mink trapped (one breeding female found) 

These numbers show a steady decline in mink captures, and as Vince pointed out, “Unlike our other conservation activities, the fewer we see of this species, the better!” 

A Mink-Free Future 

The CRT’s mink eradication efforts in Cambridgeshire represent a monumental success, not only in reducing the number of an invasive species but also in improving the conditions for native wildlife.  

Thanks to the dedication of the CRT and the partnership formed under the Waterlife Recovery Trust model, with inspired leadership from Prof Tony Martin at the Waterlife Recovery Trust, the vision of a mink-free Britain is within reach. 

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