Freshwater mussels are the most imperiled animal group in North America, with declining populations raising novel questions about invertebrate welfare at population scale.
The welfare status of freshwater mussels is uncertain but their ecological importance is clear - populations engineering aquatic habitat support thousands of other species whose welfare is more established. The biological stress responses of mussels to poor water quality, temperature extremes, and desiccation represent something that at minimum merits consideration under a precautionary welfare framework. Individual mussels can live over a century, meaning the loss of individual animals from anthropogenic causes represents both a direct welfare impact and a significant loss of ecological function. Restoration programs that improve water quality and restore river connectivity benefit mussel populations and the entire aquatic ecosystem they support.