Invasive aquatic species including Asian carp, lionfish, and signal crayfish cause ecological harm and require management. Integrating welfare considerations into control programs reduces unnecessary suffering.
Aquatic invasive species management involves killing potentially sentient fish and crustaceans to protect ecosystems, presenting a welfare dilemma parallel to terrestrial invasive species management. The precautionary principle on fish sentience suggests that management methods should be as humane as feasible while achieving ecological goals. Electrofishing, the most common removal method, causes physiological stress but typically not death if properly performed. Chemical treatments using rotenone or other piscicides cause death by oxygen deprivation over minutes to hours — a welfare cost that may be justified by ecological benefits but should be acknowledged. The development of more targeted, humane removal methods for aquatic invasives is a welfare research priority.