Ocean acidification refers to the process by which ocean water becomes more acidic due to increased absorption of carbon dioxide from the atmosphere. As CO2 dissolves in seawater, it reacts with water molecules to form carbonic acid, leading to a decrease in pH levels and making the water more acidic. This change in ocean chemistry can have significant impacts on marine life, particularly organisms that rely on calcium carbonate for their shells or skeletons such as corals, mollusks, and some plankton species. As ocean acidification progresses, it becomes increasingly difficult for these creatures to build and maintain their protective structures, leading to population declines and disruptions in marine ecosystems.