Foreign invaders threaten the natives

Trapping crayfish
Trapping crayfish
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MORPETH’S internationally important crayfish could be under threat from foreign invaders.

The River Wansbeck is one of the last strongholds for the native white-clawed crayfish as the species has been wiped out in many areas due to the spread of the American signal crayfish.

Now a large population of the American crayfish has been confirmed in the neighbouring River Blyth.

The species is bigger and more aggressive than the native crayfish, out-competes them for food and also carries a fungal disease known as crayfish plague.

It can also have a significant impact on fisheries by eating fish eggs and increases erosion of river banks through burrowing.

Environment Agency Fisheries and Biodiversity Team Leader Fiona Morris said: “We don’t yet know how far the signal crayfish have spread, but the numbers we have found recently are not good news.

“It is impossible to totally eradicate populations of signal crayfish. All we can do now is try our best to contain them and stop them from spreading to help protect our native crayfish.”

A Check, Clean and Dry campaign has been set up by the Environment Agency, Natural England, Northumberland Rivers Trust and Northumberland Wildlife Trust, calling on anglers and other river users to take extra care to stop the spread of the signal crayfish.

People should check their equipment and clothing for living organisms, clean and wash all equipment, clothing and footwear thoroughly after being in water, dry all equipment and clothing, and make sure they don’t transfer water elsewhere.

Ms Morris said: “We’re calling on all river users and anglers who fish the River Blyth to help us by checking, cleaning and drying all their fishing tackle and footwear thoroughly so that we can halt the spread of the disease that the signal crayfish carry.

“In the North East we still have native populations which are holding out against the invasion, and we want to keep it that way.”

Peter Kerr, of the Northumberland Rivers Trust, added: “We must do all we can to stop signal crayfish getting into the Wansbeck where their effect will be devastating on the native population. We would ask all anglers and river users to follow the Check, Clean, Dry campaign.”