Freshwater mussels are the most imperiled group of animals in North America, with over 70% of species threatened or extinct due to habitat degradation, raising welfare questions about the suffering of an often-overlooked group.
Whether freshwater mussels have the capacity for suffering is genuinely uncertain given their simple nervous systems. However, their ecological function in river health is unambiguous — mussel bed loss degrades water quality for all animals in river systems. The welfare of fish, amphibians, and aquatic insects in degraded mussel-free rivers is directly harmed by the ecological collapse that mussel extinction causes. Protecting freshwater mussels is therefore both directly important if mussels have any capacity for welfare, and indirectly important for the vast community of animals whose welfare depends on healthy rivers.