Threatened crayfish rescued from claws of invasive species

A threatened species of crayfish is making a comeback in Lincolnshire after the Environment Agency (EA) and conservation groups relocated them away from their invasive non-native predators.

Native white-clawed crayfish – the country’s largest freshwater crustaceans – have been in decline since non-native American signal crayfish escaped into UK waters in the 1970s. The larger, invasive crayfish outcompete native species for food and habitat and carry a disease fatal to the UK species.

The EA, the Lincolnshire Chalk Streams Project and the Lincolnshire Wildlife Trust relocated 600 white-clawed crayfish from the River Witham – where they were at risk of being wiped out – to remote locations, including a chalk stream in the Lincolnshire Wolds last July. Recent surveys revealed that the transfer was a success and that the crayfish have begun to breed.

Richard Chadd, senior environmental monitoring officer with the EA, said the 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”.

Previously the crayfish were “only present in two locations in the county,” said Chadd, adding that “we’ve potentially doubled their habitat in the space of a year”.

Ruth Craig, Lincolnshire chalk streams project officer, said the groups 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”.