An alien species of mammal is threatening the ecosystem of the region's waters, it has been warned.

Eastern Daily Press: Broads Wildlife is coming under threat from merciless American minks Picture: Wildstock/Norfolk Wildlife Trust.Broads Wildlife is coming under threat from merciless American minks Picture: Wildstock/Norfolk Wildlife Trust.

In recent years American mink, which were originally imported for their fur, have infiltrated the wildlife of the Broads and are placing some of the most precious species at serious risk.

With a lack of a natural predator of its own, the mink are left to feast on a variety of different species, largely unchallenged, and experts say they are far from fussy eaters.

Water voles, moorhens and even swans are known to have been butchered by the beasts, which as a non-native species is posing a real threat to the delicate balance of the Broads ecosystem, the Broads Authority (BA) has warned.

To manage the threat, the authority works alongside the Norfolk Mink Project, an organisation founded in 2003 to protect indigenous species from the invaders.

Gavin Devaney, BA environment officer, said: "We monitor mink activity using mink rafts and tracking clay cassettes and if an area suggests mink activity, humane traps will be set in the area.

"The mink traps are fitted with devices which notify operatives daily on the status of the trap. If an American mink has been caught, it will be humanely dispatched and recorded."

Stephen Mace, Norfolk Mink Project's co-ordinator for the Bure, Yare, Thet and Waveney, said the number of mink has been on the decline in the past year, but that their work was not done.

He said: "We understand dispatching of the mink is not the nicest thing to do, however they have such a massive impact on the environment that we are left with no other choice.

"As they do not have their own predator, they are essentially left to kill whatever they want. For example, they are able to get into water vole burrows and can wipe out entire colonies.

"Water voles themselves are so important to the waterways as they have a key role in protecting the vegetation."

While American minks have been spotted all across the Broads area in recent years, they are believed to be most prevalent in the Bure, Wensum, Waveney and Little Ouse areas.

Anybody who spots one is encouraged to contact the Norfolk Mink Project through its website.