Mussel and other bivalve farming is often promoted as a low-welfare-impact food source, but growing research into bivalve nociception and stress responses is prompting reassessment of these claims.
The welfare status of bivalves sits at the most uncertain boundary of sentience research. Unlike fish or crustaceans, the neurological case for bivalve sentience is weaker — they have no centralised brain and their nociceptive responses may be simple reflexes rather than pain experiences. However, the evidence is not conclusive, and the scale of bivalve consumption is enormous. From a welfare perspective, the honest position is one of uncertainty: bivalve farming likely carries very low welfare risk compared to vertebrate farming, and may be the lowest-welfare-impact animal protein available. For those seeking to reduce animal suffering while maintaining animal protein consumption, bivalves are a defensible choice, though continued research should inform this position as evidence develops.