Ocean acidification harms coral reefs by weakening the calcium carbonate structures that corals need to grow and survive.

Ocean acidification occurs when excess carbon dioxide (CO2) in the atmosphere dissolves into the ocean, lowering the pH of seawater. This process reduces the availability of calcium carbonate, a crucial compound that corals and other marine organisms use to build their skeletons and shells. As a result, coral reefs become more vulnerable to erosion, bleaching, and weakened structural integrity, which threatens marine biodiversity. Coral reefs are the most directly and significantly impacted by ocean acidification, while it can also affect other parts of marine life. It doesn't significantly improve fish reproduction, lower oxygen levels, or boost biodiversity.