EFFORTS are under way to save an aquatic animal which appears to be heading towards extinction in the North-East.

One of the biggest threats to the native white-clawed crayfish is the arrival in the region of the American Signal crayfish, which may have brought with it a form of plague.

Signals seem to be immune, but the disease can devastate native crayfish, which have already suffered a steep decline in numbers.

Now Durham Wildlife Trust is hoping to prevent the creature disappearing from its few remaining strongholds in County Durham and the Tees Valley.

The initiative is driven by Stuart Priestley, the trust's otters and rivers project officer, a post whose backers include Northumbrian Water, Blue Circle Industries and the Environment Agency.

Mr Priestley said native crayfish survived on central sections of the River Tees around Barnard Castle, in upland Durham dales streams and one or two ponds and lakes.

Signals are already in parts of North Yorkshire and appear to have established themselves on the River Tees. They were introduced into southern England and have now colonised many rivers, their spores often carried on angler's boots.

In many parts of southern England Signals have driven native crayfish into extinction and they are heading north.

Mr Priestley said: "We are concerned about the impact of crayfish plague and also that Signal crayfish compete with white-clawed crayfish for the same habitats.

"The problem is that no one has ever done a major survey of white-clawed crayfish in our area and we do need to find out where they are and where the Signals are.

"Although we do not know exactly where the white-clawed crayfish are, we do know that numbers are definitely dropping," he said.

"My personal opinion is that they are under threat of extinction in County Durham and the Tees Valley."

The trust hopes to raise money for a comprehensive survey and, as part of the Otters and Rivers Project, will continue to work with landowners and land managers to ensure rivers are favourable habitats.

Ultimately, said Mr Priestley, he would like to investigate the re-introduction of white-clawed crayfish in some areas.

Anyone wishing to report sightings of crayfish or companies that would like to offer financial support for the survey can contact Mr Priestley on (01388) 488728