Freshwater mussels are among the most imperilled groups of animals on Earth, with over 70% of North American species at risk, facing extinction from habitat degradation while welfare science on their capacity for suffering remains nascent.
The welfare status of freshwater mussels is philosophically uncertain — their nervous systems are far simpler than those of vertebrates and the evidence for pain experience is weak. However, from a conservation perspective, the loss of these animals represents an enormous ecological and ethical concern. The conditions that kill mussels — oxygen depletion, sedimentation, chemical pollution — likely cause a deteriorating physiological state that precedes death over extended periods. Even setting aside the question of individual suffering, the elimination of entire species represents an irreversible harm to biodiversity. Applying a precautionary approach to mussel welfare, particularly in terms of habitat protection and water quality, costs little and preserves enormous value.