Our white-clawed crayfish in rivers across East Anglia are under threat

A lake in Suffolk is being established as a safe haven “ark” for the British native white-clawed crayfish which is under threat from an American invader.

The crustaceans look like miniature lobsters and used to be widespread in Britain’s rivers. However, their numbers have fallen sharply due to the rise of the aggressive signal crayfish. The Environment Agency is transferring white-clawed crayfish to a “secret” lake which will become an “ark” home.

The crayfish will be rescued from rivers in Suffolk, Norfolk, Essex and Cambridgeshire.
The invading species out-competes the white-claws for food and other resources as well as carrying a disease called crayfish plague.

Lethal disease
An Environment Agency spokeswoman said: “Although the signal crayfish are not affected, this disease is lethal to our native species and has wiped them out from whole river systems in a matter of weeks.

“The new project is aiming to prevent this by developing an innovative crayfish ‘ark’.

“The Environment Agency, Suffolk Wildlife Trust, the Farming and Wildlife Advisory Group (FWAG) and Suffolk Biodiversity Partnership have joined forces and have already found one landowner keen for his lake to become the first ‘ark’.

“The lake has been thoroughly checked for suitability and passed with flying colours.
“Even nearby rivers were checked for non-native crayfish to ensure there was no risk of the new site being invaded.”

The spokeswoman said the project was being supported by funding from Suffolk Environmental Trust, Essex and Suffolk Water and the Environment Agency.

She said: “In time, it is hoped that the transferred animals will breed and grow into a healthy population in this lake.”

The Environment Agency has appealed for anyone with a large pond, lake or gravel pit who would like it to be considered as an ark site to contact them.