What is Ocean Acidification?
Ocean Acidification is a decrease in the ocean pH caused by the dissolution of the anthropogenic CO2 in ocean waters. The ocean presently takes up about 40% of the anthropogenic CO2 emitted to the atmosphere from human activities. The increase in the concentration of CO2 in the atmosphere is increasing its flux across the air−sea interface, which is resulting in a decrease in the pH of ocean water from the present level of 8.1 to 7.8 by the end of the century.
Average global surface ocean pH has already fallen from a pre-industrial value of 8.2 to 8.1 corresponding to an increase in acidity of about 30%. This increase is 100 times faster than any change in acidity experienced by marine organisms for at least the last 20 million years.
There is a natural equilibrium between the CO2 concentrations in the atmosphere and the oceans, but this equilibrium is changing due to the large amounts of CO2 entering the ocean which overwhelms the ocean natural ability to buffer itself.
What are the effects of Ocean Acidification in marine life?
Ocean acidification poses a variety of risks for coral reef ecosystems and those organisms generating shells, tests or skeletons out of calcium carbonate (CaCO3). It will increase the dissolution or erosion of existing coral reef structures, increase algal abundance, and decrease reef growth by reducing calcification rates, reproduction and recruitment of reef organisms. It will be more difficult for oysters, clams, mussels, sea urchins, phytoplankton and zooplankton to build and maintain their shells, because the concentrations of CaCO3 will decrease. Basic bodily functions of all marine organisms are going to be affected by changing seawater chemistry.