EXCLUSIVE: Crayfish threat hits Cumbria

One of Cumbria's rivers faces a potential environmental disaster with the discovery of a population of North American Signal Crayfish.

It is the first time the foreign intruders have been found in the River Eden in Carlisle.

The fear is they could wipe out the endangered native white clawed crayfish.

It is already a big problem across the border in Scottish waters.

Kim Inglis has this report: