The Chemistry of Acidification
As atmospheric CO2 levels rise, oceans absorb approximately 30% of this carbon dioxide, leading to acidification. This process threatens marine organisms with calcium carbonate shells, including corals, mollusks, and some plankton species, potentially disrupting entire food webs.
When CO2 dissolves in seawater, it forms carbonic acid, which lowers the ocean's pH. Since the Industrial Revolution, ocean pH has dropped from 8.2 to 8.1—a 30% increase in acidity.
Impact on Marine Life
Organisms that build shells or skeletons from calcium carbonate are particularly vulnerable. As ocean acidity increases, less carbonate is available, making it harder for these organisms to form and maintain their protective structures.
Affected Organisms
- • Corals: Reduced calcification rates, weaker skeletons
- • Mollusks: Thinner shells, reduced growth
- • Plankton: Base of food web disruption
Ecosystem Consequences
The effects of acidification cascade through marine ecosystems. When foundational species like corals and plankton are affected, entire food webs can be disrupted, affecting fish populations and ultimately human food security.
Addressing ocean acidification requires global action to reduce CO2 emissions, as well as local efforts to reduce other stressors on marine ecosystems.