Coral reefs are living ecosystems that support extraordinary biodiversity, with the welfare of individual coral animals and reef fish affected by bleaching, ocean acidification, and physical damage.
Corals themselves are animals with simple nervous systems whose welfare status is uncertain but warrants precautionary consideration. The bleaching process involves corals expelling their zooxanthellae partners under thermal stress, leaving them white and ultimately causing death if stress continues. Bleaching is acutely stressful even if corals do not experience this in the way vertebrates would. More certain are the welfare impacts on the billions of fish, invertebrates, and other animals whose entire ecological existence depends on reef structure. When reefs die, the complex habitat that supports these species disappears. Crown-of-thorns starfish outbreaks, physical damage from boat anchors and snorkelers, and destructive fishing all harm coral reef ecosystems.