Freshwater mussels including the critically endangered freshwater pearl mussel are among the most threatened animals in Europe, with habitat degradation threatening both populations and raising welfare questions.
Freshwater mussel welfare sits at an extreme scientific frontier. These animals lack the complex nervous systems that characterise species with clear sentience evidence, yet they are long-lived, ecologically important, and subject to population collapse through human activity. The welfare question for freshwater mussels is less about individual suffering and more about the ethical implications of allowing populations to collapse through habitat degradation. From a conservation ethics perspective, allowing functionally immortal animals with 100+ year lifespans to be killed by agricultural pollution represents a large-scale elimination of individual lives. The restoration of pearl mussel populations through river restoration and captive breeding is primarily conservation but has welfare dimensions for the individuals involved.