Freshwater pearl mussels are among Britain's most endangered invertebrates, with populations devastated by pollution, habitat change, and illegal collection, raising both conservation and welfare considerations.
The welfare status of molluscs including freshwater pearl mussels remains scientifically uncertain, though their capacity for nociception and basic stress responses warrants consideration under precautionary welfare principles. More immediately, the conservation of these extraordinary long-lived invertebrates requires addressing the welfare of the river ecosystems they inhabit, including the salmonid fish that host their larvae. Restoration of pearl mussel habitat through improved water quality, removal of barriers to salmonid migration, and reduction of fine sediment delivers welfare and conservation benefits simultaneously for multiple species.