SCIENTISTS from York have given the go-ahead to fishermen wanting to eat their crab catch from the River Ouse.

Researchers at the Central Science Laboratory, in Sand Hutton, near York, have been assessing the potential health risks of eating Chinese mitten crabs.

The oriental invader was introduced into western Europe in the early 20th century and sightings of the crab have been reported in the River Ouse since the 1980s.

The creatures can burrow themselves into fragile mud riverbanks, riddling them with holes until they collapse – posing a threat to York’s flood defences.

But thanks to the research of the Sand Hutton scientists, the crabs – which are a culinary delicacy in south-east Asia – could now be harvested for gastronomic use as a commercially viable way of controlling the species.

A spokesperson for the Central Science Laboratory said: “Although the work focuses on crabs found in the River Thames in London, it may also address an issue of local interest.

“York anglers have been urged to be on the lookout for mitten crabs after a York fisherman recently caught one in the River Ouse, near Bishopthorpe. “The crabs can cause serious structural problems by burrowing into fragile mud riverbanks, and could be bad news for York’s flood defences.”

The study was carried out in partnership with experts from the London Port Health Authority, the Natural History Museum, Cefas and the Food Standards Agency.

The scientists gathered information about concentrations of toxic metals and organic chemical contaminants to find out whether the crabs were suitable for human consumption.

Their research found that the crabs were safe to eat.

The spokesperson said: “Despite the presence of dioxins, it is unlikely that enough crabs would be eaten by any individual to be a risk to health, especially given that portions are small and mitten crabs are only available for eating for three or four months each year.

“However, the Food Standards Agency already advises that girls and women up to child-bearing age should not eat excessive amounts of crab, and this applies equally to the meat of mitten crabs.” The crab is so named because one of its distinguishing features – its large hairy claws – are said to resemble mittens.

A spokeswoman for the Environment Agency said the creatures were not known to be causing any structural damage to the banks of the River Ouse yet, but she said they were monitoring the situation.

However, she said that the Environment Agency did not believe that creating commercial fisheries would help to control the species.

She said: “We would oppose the commercialism of Chinese mitten crab fishing because it might encourage the spread of the mitten crab to other areas.”