Lifeline for endangered crayfish as National Trust creates first ‘Ark’ site

Lifeline for endangered crayfish as National Trust creates first ‘Ark’ site - National Trust

A native White-clawed crayfish at Wallington, Northumberland © National Trust Images/Annapurna Mellor

One of the UK’s most endangered native species has been given a fresh chance of survival thanks to a newly created refuge on a National Trust estate.

An old cattle drinking hole at Wallington in Northumberland will become the charity’s first ‘Ark’ site for the white-clawed crayfish, the country’s only indigenous crayfish.

Often compared to a miniature lobster in appearance, the white-clawed crayfish is so vulnerable that experts fear it may become extinct.

Populations have more than halved across Europe in recent decades largely due to the spread of the American signal crayfish, a bigger species which was introduced to the continent in the 1970s as a restaurant delicacy.

As well as outcompeting white-clawed crayfish for food and habitat, the signal crayfish carries a deadly plague that while harmless to itself, can decimate white-clawed populations in a matter of weeks.

Now the National Trust hopes to give the native species a lifeline by moving up to 100 of the crustaceans into an ‘Ark’ site – a safe waterbody where it is hoped they will breed.

The crayfish will be taken from the River Wansbeck which runs through the estate and is deemed to be one of the best habitats for white-clawed crayfish left in the UK.

Rangers have spent 15 months taking water samples, surveying, applying for a handling licence and most recently, turning the 200-year-old cattle drinking hole into an ideal home for the crayfish, using dry-stone walling techniques to create crevices that imitate their natural habitat.