Freshwater mussels are the most imperiled group of animals in North America, with their decline removing critical water filtration services and habitat structure that countless other species depend on.
The moral status of freshwater mussels is uncertain — they have rudimentary nervous systems that likely do not support rich subjective experience. However, their ecological welfare role is profound: mussels are keystone species whose loss degrades water quality, removes habitat structure, and eliminates food sources for hundreds of fish, bird, and mammal species that have clear welfare interests. The cascading welfare consequences of mussel decline — through degraded water quality, simplified habitats, and reduced prey availability — affect the welfare of countless vertebrate animals. Mussel conservation is therefore both a biodiversity and an indirect animal welfare priority.