The freshwater pearl mussel is one of Britain's most endangered animals, with populations having declined by over 90%. Their conservation connects to river health, salmon populations, and agricultural pollution control.
Freshwater pearl mussel welfare and conservation overlap significantly given the species' sentience uncertainty. While mussels likely have limited pain experience compared to vertebrates, their conservation connects directly to fish welfare through the salmon-mussel parasitism relationship: pearl mussel conservation requires healthy salmon populations, which in turn requires welfare-positive fisheries management. Agricultural runoff that kills pearl mussels also harms fish through reduced water quality and siltation. River health restoration for pearl mussel conservation therefore delivers co-benefits for multiple species with clearer welfare significance.