Freshwater mussels and clams are among the most endangered animal groups on Earth. Their welfare capacity and conservation status raise important ethical questions.
Whether freshwater mussels can suffer is genuinely uncertain. They lack a centralised brain and have only dispersed ganglia, making it unlikely they have subjective experience comparable to vertebrates. However, they respond to environmental insults including pollution and temperature extremes with measurable physiological stress responses. From a conservation perspective, the near-extinction of many freshwater mussel species represents a catastrophic loss of biodiversity driven by habitat alteration, pollution, and dam construction. Even if individual mussels cannot suffer, the ecological welfare of entire river systems depends on their presence as ecosystem engineers.