August 14, 2018 3.58 pm This story is over 62 months old

Native crayfish make a comeback

“These crayfish are a vital part of our ecology”

A protected species of fish has been transferred to new locations in the Lincolnshire Wolds to increase its chances of survival.

White-clawed crayfish, named for the pale colour of the underside of their claws, are the country’s largest native freshwater crustaceans.

Last July, 600 white-clawed crayfish were moved from locations in the River Witham because they were at risk of being wiped out by invasive signal crayfish.

A species under threat?

Native white-clawed crayfish have been in decline since non-native American signal crayfish escaped into UK waters in the 1970s.

These larger, invasive crayfish outcompete native species for food and habitat and carry a disease fatal to the UK species.

The Environment Agency is working with partners including the Lincolnshire Chalk Streams Project and the Lincolnshire Wildlife Trust to help secure the future of the species by relocating them to areas free of the invaders.

Surveying for crayfish. Photo: Environment Agency

The first transfer of the protected species to the new locations, including a chalk stream in the Lincolnshire Wolds, was deemed a success and the crayfish have started to breed.

Senior environmental monitoring officer at the Environment Agency, Richard Chadd, said: “These crayfish are a vital part of our ecology, so preserving them is yet another example of how we’re protecting our environment for the future.”

“Having personally worked on this project – physically picking up these crayfish, measuring them, checking their health and relocating them to their new homes – I’m thrilled that our efforts at protecting them have been so successful.

“Previously the crayfish were only present in two locations in the county, so we’ve potentially doubled their habitat in the space of a year – and Lincolnshire’s rare, protected chalk streams are the perfect home.

“They’re remote, clean, and the water is high in calcium, which helps crayfish form strong exoskeletons and makes them more robust.”

Lincolnshire Chalk Streams Project Officer, Ruth Craig, added: “We worked closely with local landowners to secure access and their long-term support in protecting the area from disturbance, and we will return to monitor the populations as needed. But the hard work doesn’t end here – we plan to continue identifying further possible locations, supporting the work of the EA.”