Beyond oysters and mussels, farmed shellfish include species like abalone and scallops whose welfare status requires careful consideration.
The welfare status of abalone and scallops is more uncertain than for bivalves like mussels and oysters, but their more complex nervous systems suggest greater precautionary consideration. Abalone, in particular, show behavioral complexity including homing behavior, escape responses, and aggregation that suggests more sophisticated information processing than bivalves. Whether this translates into morally relevant welfare experiences is uncertain. The precautionary principle - taking protective action under uncertainty when potential suffering is significant and prevention is feasible - supports applying some welfare consideration to farmed abalone and scallops. Live transport and holding practices that minimize stress, and slaughter methods that cause rapid death rather than prolonged asphyxia, represent reasonable welfare improvements under uncertainty.