The Pacific blue mussel (Mytilus trossulus) is a foundational and beneficial species in the intertidal environments of the northern Pacific Ocean. Comparative physiologists have recently studied how two aspects of climate change—warming temperatures and increasingly acidic waters—may affect this ecologically important species. The scientists present their findings this week at the American Physiological Society (APS) Intersociety Meeting in Comparative Physiology: From Organism to Omics in an Uncertain World conference in San Diego.