Freshwater pearl mussels are among the world's most endangered animals and require clean rivers and salmon hosts to survive.
Freshwater pearl mussels are so dependent on specific water quality and host species that their welfare is entirely determined by river ecosystem health. Their near-extinction in most European rivers reflects decades of agricultural pollution, sedimentation, and over-abstraction. Welfare improvement for individual mussels is not achievable without restoring the river conditions that allow them to survive and reproduce. The welfare of this species is inextricably linked to salmon welfare, river restoration, and agricultural pollution reduction.