Freshwater mussels are among the most imperiled animals on Earth. As filter feeders and ecosystem engineers, their welfare and conservation depend on clean water and intact river ecosystems.
Freshwater mussel welfare and conservation are at the intersection of the most biologically complex welfare questions. As bivalves, the evidence for sentience is limited, but mussels are sentient enough to respond to environmental changes and play vital ecosystem engineering roles. Their conservation matters profoundly for biodiversity and ecosystem function. Dams block the host fish that mussel larvae must parasitize to complete their life cycle, making dam removal the most transformative conservation action. Pollution causes mussel die-offs that eliminate populations developed over centuries. Mussel restoration programs that propagate larvae and reintroduce them to restored habitats have shown success in some river systems.