Ocean acidification from CO2 absorption is altering marine chemistry in ways that impair the physiology, behavior, and welfare of fish, corals, and invertebrates.
Ocean acidification affects marine animal welfare through physiological impairment — fish in acidified water show confusion, reduced predator avoidance, and altered sensory processing that increases their vulnerability to harm. Shellfish unable to form adequate shells may experience reduced survival. The scale of habitat alteration from acidification affects billions of individual marine animals simultaneously, making climate action the most important marine welfare intervention.