Freshwater Wildlife

White-clawed Crayfish Welfare and Crayfish Plague in UK

White-clawed crayfish, the only native UK crayfish, are endangered due to crayfish plague carried by introduced American signal crayfish. The disease causes 100% mortality in affected populations, creating catastrophic welfare events.

Key Facts

White-clawed crayfish are the only native freshwater crayfish in the British Isles
American signal crayfish were introduced in the 1970s for aquaculture and carry crayfish plague
Crayfish plague (Aphanomyces astaci) causes 100% mortality in white-clawed populations
White-clawed crayfish are legally protected under the Wildlife and Countryside Act 1981
Ark sites on isolated streams protect disease-free refuge populations

Welfare Considerations

Crayfish plague causes rapid, complete mortality of white-clawed populations, often wiping out decades of individuals within weeks. Affected animals experience progressive loss of coordination, muscle spasms, and death. The combination of rapid population extinction and individual suffering makes crayfish plague events among the most severe acute welfare events in UK freshwater ecology.

What You Can Do

Never move equipment, nets, or boats between waterways without disinfection (Check Clean Dry)
Report American signal crayfish sightings to the Environment Agency
Support white-clawed crayfish captive breeding and ark site programs
Donate to Buglife and Wildlife Trusts crayfish conservation work
Advocate for stronger regulations on ornamental crayfish trade