The main threat to coral reefs in U.S. coastal waters is ocean acidification and warming, driven by climate change.

Coral reefs in U.S. coastal waters, such as those in Florida, Hawaii, and the Pacific territories, face significant threats from ocean acidification and warming caused by climate change. Rising sea temperatures lead to coral bleaching, a process where corals expel the algae they rely on for food, leaving them vulnerable to disease and death. Simultaneously, increased carbon dioxide levels lower ocean pH, causing acidification, which weakens coral skeletons and hampers growth. Additional stressors, such as pollution, overfishing, and coastal development, exacerbate the decline of these critical ecosystems. Protecting reefs requires global carbon emission reductions and local conservation efforts.