Stressors

What is acidification

Ocean Acidification (OA) is a pressing environmental concern that affects the health of our oceans and the people who use them.

Overview

Why It Matters

Carbon dioxide gas dissolves so readily in seawater that approximately one quarter of human caused CO₂ emissions become sequestered in the ocean. Once in the ocean, CO₂ combines with water to form a weak acid, resulting in a change in the chemistry of the sea.

The Chemistry of Ocean Acidification

The other major change in seawater chemistry involves CO₂-driven changes in the solubility of calcium carbonate minerals (CaCO₃) used by many marine plants and animals to build their shells and skeletons.rnrnThe solubility of CaCO₃ minerals depend on the amount of dissolved carbonate ions in seawater.rnrnMore CO₂ and lower pH reduces the concentration of carbonate ions, making it more difficult for many organisms to make shell material.

Ocean CO₂ and pH from NOAA: Correlation between rising levels of CO2 in the atmosphere at Mauna Loa with rising CO₂ levels in ocean at Station Aloha. As the CO₂ increases, the pH decreases; indicating increasing acidificication.

Ocean Acidification Is One of Many Human Impacts Changing Marine Ecosystems