The white-clawed crayfish is Britain's only native crayfish species, now critically threatened by invasive signal crayfish and the disease they carry.
The welfare implications of crayfish plague are severe: infection causes rapid death in native crayfish populations, sometimes wiping out entire river populations within weeks. Conservation efforts including ark site establishment and signal crayfish control help protect surviving populations. Signal crayfish control often involves trapping and killing, presenting its own welfare considerations. Preventing introduction and spread of non-native crayfish through equipment biosecurity - washing and drying between water bodies - is the single most important action individuals can take.