A COLONY of endangered white-clawed crayfish has been found in the Leeds and Liverpool Canal near Gargrave.

Around 150 of the native species, which are now protected after suffering a major decline, were found when a section of the canal at Bank Newton was drained to carry out repair work.

Staff from the Canal and River Trust saved the crayfish and moved them to another section of the canal.

“This was a really important discovery for us as we’ve done a couple of crayfish investigations and found very few," said Phillipa Baron, trust ecologist.

"They have been depleting in numbers over the last 30 years since the American signal crayfish were brought to England as fashionable seafood."

The white-clawed crayfish is one of the UK's largest freshwater invertebrates and is the only native crayfish. It can grow up to 12 centimetres long and looks like a mini-lobster, but is not generally thought of as safe to eat because it is omnivorous and not particularly fussy about what it eats.

“The hidden underwater crevices which our dry stone walls provide are ideal habitats for them. It’s therefore crucial we do what we can to protect their populations and the most direct way we can help is to ensure their survival during and after our repair works and relocate them to safe sites," added Ms Baron.

“Sadly, at the moment there is no known way to eradicate the non-native crayfish which have become very dominant because of their predatory instincts and the plague they’ve spread.”

Following a virulent outbreak of the Aphanomyes Astaci plague in the 1970s the white-clawed crayfish has been on a steady decline. The plague, started by the invasive signal crayfish species from North America, has spread across the UK’s waterways and is widely expected to wipe out large populations.

The trust is currently carrying out a £45 million, five month maintenance programme to 2,000 miles of waterways across England and Wales. It carries out restoration and repairs to locks during the quiet time between November and March.