Crayfish are farmed globally for food, but their welfare is rarely considered despite growing scientific evidence for their capacity to experience pain and stress.
Crayfish welfare sits at an important ethical frontier. Scientific evidence suggests these decapod crustaceans have the neurological capacity to experience pain and stress - they learn from painful experiences, show wound-tending behaviour, and produce opioid compounds in response to injury. Despite this, crayfish are not covered by EU or UK animal welfare legislation in farming contexts, and are routinely killed by methods that would cause prolonged suffering if applied to vertebrates. Boiling alive without prior stunning subjects crayfish to high heat that takes minutes to cause death - a period during which pain responses continue. High-density farming causes aggression-related injuries and stress. The UK additionally faces a complex situation with invasive signal crayfish, where trapping and killing is ecologically necessary but welfare standards for trapped animals are minimal. Decapod welfare science has advanced rapidly, and policy is beginning to follow: the UK Animal Welfare (Sentience) Act 2022 included decapods following a government-commissioned review.