Clams, cockles, and other filter-feeding bivalves are farmed with minimal environmental impact. Their welfare status is the subject of scientific debate, but available evidence places them at low sentience probability.
Clam and cockle welfare sits at the low end of sentience probability on current evidence — their simple decentralised nervous systems make conscious suffering less likely than for vertebrates or decapod crustaceans. This does not eliminate the welfare question entirely, as our understanding of consciousness and sentience at the margins of the animal kingdom is incomplete. From a practical standpoint, precautionary welfare measures for bivalves are low-cost and include avoiding prolonged air exposure, using rapid thermal processing, and minimising mechanical damage during harvest. For consumers and producers making comparative welfare choices, bivalves represent a substantially lower welfare risk than vertebrate animal products, making them a reasonable component of a welfare-conscious diet.