Scallops and oysters are harvested in vast quantities. Whether they can suffer is genuinely uncertain — but their ecological importance and the methods used to harvest them deserve consideration.
The welfare capacity of oysters and scallops is genuinely uncertain given their extremely simple nervous systems. Most animal welfare scientists consider them unlikely to have subjective experiences, but the precautionary principle suggests caution. The primary welfare concern with scallop fisheries is ecological — scallop dredges destroy seabed habitat and kill vast numbers of non-target benthic organisms with certainty of welfare significance. Oyster farming is generally considered low-welfare-impact compared to most animal food production, though invasive species risks and anti-fouling practices deserve monitoring. The restoration of oyster reefs represents a genuine win for marine ecosystem welfare at scale.