species and provide essential coastal protection.
Ocean acidification presents another serious threat. As seawater absorbs carbon dioxide, its chemistry changes and carbonate ions become less available. This makes it harder for oysters, crabs, corals, and certain plankton to build and maintain their shells or skeletons. These changes can disrupt marine food webs and threaten commercially important fish populations.
Climate change also contributes to ocean deoxygenation. Warmer water holds less dissolved oxygen, while stronger stratification limits the mixing of oxygen-rich surface water with deeper layers. Expanding low-oxygen
