Photo of swimming mink: Credit Ian Preston / WRT
The invasive non-native American Mink is a vicious predator which has caused the loss of a wide range of river wildlife in Great Britain, particularly Water Voles which were once a common sight on the Ivel, but no more.
Started by a remarkable group of people in Norfolk just a few years ago, the long-term aim of the Waterlife Recovery partnership was a Mink-free GB.
The task is quite exceptional. Mainland Great Britain (England, Wales & Scotland) covers an area of 209,332 sq km. The largest successful invasive mammal eradication operation Worldwide up to now removed Coypu from some 20,000 sq km in East Anglia. Not unreasonably, the ambition of total Mink eradication over such a vast area was scoffed at by some, and a dream of dubious feasibility for even the most starry-eyed. They decided to start by seeing what a coordinated campaign could achieve in East Anglia, and then decide whether to expand the work geographically.
The Waterlife Recovery East project (WRE) has since exceeded even the most optimistic predictions, it's an exemplar of what can be achieved by ‘Citizen Scientist’ volunteers and great partners. Its success quickly attracted interest from afar. Today, partner organisations and volunteers are trapping Mink and seeing native wildlife rebound from Yorkshire to Sussex, and more counties are signing up at pace.
In 2022 WRE formed a new charity to offer coordination and leadership and seek funding for a national campaign. The Waterlife Recovery Trust (WRT) was granted charity registration in 2022, and became fully operational at the beginning of 2023.
Meanwhile, The Environment Act 2021 includes a legally binding target on species abundance for 2030, Water Voles are one of the target species, and Natural England (NE) is the government agency tasked with implementing it in England. Thus far, NE has contributed to the WRT trapping effort in East Anglia, but has still not committed to the kind of national plan espoused by WRT and already shown to have transformed the conservation prospects of Water Voles over 10% of England.
Instead, NE has busied itself in funding various projects to improve habitats for Water Voles, but they are effectively useless if there are still Mink in the area. Nevertheless, there are some encouraging signs that the WRT model of Mink eradication is being recognised within the agency. Water Voles must hope that the Species Recovery Team - entrusted with saving them nationally - will actually do something about the creature that is so effectively killing them. There is still a realistic prospect of success by 2030, but they need to act now.
Traditionally, to catch Mink, one would put out clay pads and you would go and inspect them every now and again. If a pad was found with Mink paw-print impressions in it, the pad would be replaced by a trap. These traps then had to be visited every day, which was very labour intensive. The complete game-changer has been the introduction of continuously active smart traps which instantly report via cellular messaging when they are triggered.
In coordination with the Herts & Middlesex Wildlife Trust, revIvel has two of these continuously active smart traps on the upper Ivel in Radwell.
With smart traps, the clay pads are no longer needed, you just put out a trap and wait for it to catch something. They are cage traps, specifically designed to catch Mink, but if something other than a Mink is caught it can quickly be released unharmed. These new traps have allowed a huge number of them to be deployed, WRT has 370 of them in Norfolk alone, and where they were once trapping dozens of Mink, the trapping effort to catch just 5 Mink over the last 12 months is an amazing 345 trap years. (One trap day being a trap open and available to catch an animal for 24 hours). This means there are very few Mink left in Norfolk and shows that volunteers working together on a project can make a huge difference to the environment in quite a short time.
Of course you may eradicate Mink from an area, but they do have legs and will travel; but how far or how fast nobody really knew. NE has recently renewed their support for Prof Bill Amos and Dr Angela Trowsdale's fascinating work at Cambridge University looking at the mitochondrial DNA of trapped Mink. This is the DNA that you inherit only from your mother, so it tracks maternal lineages through time. It's early days, but the latest edition 3 of the WRT newsletter describes how their sample of 543 animals from eastern and southern England is already producing some intriguing results.
We recommend you sign up to receiving the WRT quarterly newsletters, they are really very inspirational.
WRT also have a new reporting system, so if you see a Mink anywhere in the country, dead or alive, and especially on or near the Ivel, then please report it. If you don't know what one looks like or how they differ from an Otter, then the WRT website has an excellent Identification section.
Credit for much of the text above goes to Tony Martin, Chair of the Waterlife Recovery Trust Board of Trustees