Ocean acidity refers to the acidity of ocean water caused by carbon dioxide (CO2), which dissolves into the seawater from the atmosphere, forming a weak carbonic acid. It is also called “ocean acidification” or “ocean de-alkalization.”


The change in acidity changes the ocean’s chemistry in ways that affect marine life. For example, in more acidic waters, the shell-forming ability of some species such as planktons and corals is affected.

Although the acidity of seawater is naturally variable, human activities since the Industrial Revolution have increased its acidity by about 30%.The increase in acidity results in the extinction of many sea creatures, a decrease in other marine life, and the stability of the ocean floor.