Invasive signal crayfish have devastated native white-clawed crayfish populations across Europe, creating a conservation crisis that involves difficult welfare trade-offs in the management and control of invasive individuals.
Invasive crayfish management presents a genuine welfare dilemma: the conservation necessity of controlling signal crayfish to protect native species welfare conflicts with the welfare interests of individual signal crayfish. Signal crayfish are capable of nociception and may experience pain, making lethal control a welfare consideration. The conservation-welfare calculus here must consider the population-level welfare of native crayfish species facing extinction against the individual welfare costs of control measures. Most welfare frameworks accept lethal control of invasive species for conservation purposes when performed humanely, but the humaneness of killing methods for crustaceans deserves continued scientific attention.