An alien invader has been discovered in Carlingwark Loch.

The North American signal crayfish has been found at the Castle Douglas beauty spot, having been present in Loch Ken for more than a quarter of a century.

The crayfish are a threat to existing fish stocks as they can adapt to any freshwater habitat and out compete many native species. The only way of eradicating them is using biocides which also kill all other creatures in the water.

Their presence in the Glenkens has caused problems for anglers and many users and they also bury into the banks of lochs and rivers.

A joint statement from the Galloway Glens Scheme, Galloway Fisheries Trust, SEPA and NatureScot said: “It was inevitable that over time the crayfish would spread themselves into new areas of the River Dee system, particularly downstream of Loch Ken.

“It has now been confirmed that they are in Carlingwark Loch.