Bivalve mollusk farming is often proposed as a sustainable low-welfare food option, but the scientific debate about molluscan sentience requires applying a precautionary approach.
Bivalves including mussels, oysters, clams, and scallops are often considered welfare-neutral food because of the assumption that they lack sentience. However, emerging research suggests more caution is warranted. Bivalves have nociceptors, respond behaviorally to tissue damage, and show some evidence of pain modulation. Scallops in particular show dramatic escape responses to predators suggesting more sophisticated sensory processing. Boiling mussels alive, as commonly practiced in cooking, would cause prolonged harm if they are sentient. Killing by chilling before cooking is a more welfare-conscious approach. The significant uncertainty warrants applying the precautionary principle. Bivalve aquaculture does offer genuine environmental sustainability advantages over many other protein sources even accounting for welfare uncertainty.