At least 100 white-clawed crayfish, the UK’s only native species, have been found dead since the end of September

A “rescue mission” for native crayfish is under way in Northumberland after a population were found dead with mysterious patches on their shells.

The Environment Agency is working to save the internationally important species of native white-clawed crayfish in the River Wansbeck by searching for females with eggs to be taken and reared in a hatchery.