Freshwater pearl mussels are among the longest-lived invertebrates and among Europe's most critically endangered species, with welfare dependent on exceptional water quality.
While mussel sentience is uncertain, their extreme longevity makes each individual's loss from environmental degradation represent enormous potential life lost. Freshwater pearl mussel conservation requires addressing entire river catchment management including agricultural run-off, that affects water quality. The interdependence with salmon and trout creates a welfare ecosystem linking multiple species.