Wildlife

White-Clawed Crayfish: Britain Native Species Under Threat

White-clawed crayfish are being eliminated from British rivers by invasive signal crayfish and crayfish plague.

Key Facts

White-clawed crayfish have declined by 95 percent over the last 30 years
Invasive signal crayfish from North America carry plague that is lethal to white-claws
White-claws require clean well-oxygenated streams with rocky substrate
Refuge populations are being maintained on crayfish-plague-free islands and reservoirs
They are legally protected and require a licence to handle

Welfare Considerations

White-clawed crayfish face elimination from plague in areas where signal crayfish have colonised. Moribund crayfish affected by plague suffer respiratory distress before death. Conservation translocations involve capture and movement stress. Signal crayfish cause direct welfare harm through competitive displacement and physical aggression. Pollution of streams causes physiological stress and kills crayfish in affected reaches.

What You Can Do

Never transfer water, equipment, or animals between watercourses to prevent plague spread
Report white-clawed crayfish sightings to Environment Agency to help map refuge populations
Support Buglife crayfish conservation projects that protect plague-free refuges
Advocate for licensing reforms that enable more effective signal crayfish control
Participate in citizen science surveys to monitor white-clawed crayfish populations