White-clawed crayfish are critically endangered in Britain due to invasive signal crayfish carrying crayfish plague. Managing this conflict raises welfare questions about both native and invasive species.
The white-clawed crayfish welfare crisis involves an existential threat from a disease-carrying invasive species. Crayfish plague causes rapid death in infected white-clawed crayfish. Signal crayfish killed as part of invasive management programmes experience welfare harm during trapping and killing. The challenge of eliminating a widely established invasive from river systems means that ongoing signal crayfish control causes continuing welfare harm in exchange for incremental protection of native crayfish. Refugia management in plague-free catchments is the most welfare-efficient current strategy.