WORCESTERSHIRE is safe from an exotic Chinese crab threatening to take over the country's major waterways, environment experts say.

A recent study has revealed that mitten crabs, which can grow to the size of a dinner plate and prey on British native species, could threaten other marine life.

Newcastle University researchers predict that the crab - named because its claws are coated with small clumps of dark brown fur, like gloves - has the potential to establish itself in all major UK estuaries in several years' time.

But Peter Crankshaw, the spokesman for the Environment Agency in the Midlands region, said there was no

sign of the species having invaded the waters of the River Severn as yet.

He said: "There is no immediate threat from them in our region at the moment.

"We're concerned because they burrow into banks and we have flood defence banks so that has an effect on that.

"Certainly, though, for this area we're safe from them for some time."

Mr Crankshaw said the invaders were largely in the south-east in the Thames and in parts of Devon.

However, he said he could not rule out them appearing in the Severn in the future as their larvae is carried on the sea currents, which run clockwise around the country.

He added: "There's a possibility it may get to the Severn but we're not talking months or even years - we're talking quite a substantial length of time away."

The study carried out by Newcastle University compared how the crabs swept through continental Europe in the last century with their progress through British waters today.

It recommends a nationwide monitoring and trapping system should be introduced before it is too late to control the population.