'Weedy crayfish' moved to secret location in Lincolnshire
Hundreds of crayfish are being moved to "a secret location" in a bid to protect them from a non-native species.
The endangered white-clawed crayfish are being killed off by American signal crayfish which were introduced to the UK in the 1970s.
Richard Chadd, from the Environment Agency, said: "They are rather smaller and weedier than the ones that have come in."
He said moving them would give them the best chance of survival.
The signal crayfish was brought to Britain as a food source, but escaped into local waters. It outcompetes the smaller, native species for food and habitat and carries a disease fatal to the UK species.
"That was the reason they brought them in because they are bigger and are worth eating," Mr Chadd said.
About 350 of the crustaceans are being moved from the River Witham in Grantham to a private lake in the Lincolnshire Wolds,
The new site is free of the larger, more aggressive, invasive signal crayfish.
"It's really to give them the biggest chance of survival," Mr Chadd said.
"We just want them to be left alone to breed happily."
This is the second such rescue in the county after a similar effort in 2017 saw hundreds of crayfish successfully transferred to chalk streams in the Lincolnshire Wolds.
Surveys carried out in the area since have confirmed the crayfish are breeding and boosting the population.
The Environment Agency is working with the Lincolnshire Chalk Streams Project and the Lincolnshire Wildlife Trust .