Bivalve molluscs including mussels and oysters are farmed in vast quantities and are increasingly examined for their potential capacity to experience nociception or suffering.
The welfare status of farmed bivalves remains genuinely uncertain but the weight of scientific evidence currently suggests they lack the neural complexity to experience suffering in a morally significant sense. This makes bivalves an interesting case in welfare ethics: they may represent an animal-sourced food with very low welfare cost, making them a reasonable option within a diet reduced in animal products. However, the precautionary principle suggests maintaining some degree of uncertainty and supporting research into bivalve nociception. Environmental impacts of bivalve farming - which can be positive given their filter-feeding nature - are also a relevant consideration.