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Discovering how coral reefs respond to acid oceans

Coral reefs are ecologically and economically important marine habitats, but they are threatened by a host of human-induced stressors including ocean acidification. When acidification occurs, an increase in dissolved carbon dioxide causes the oceanic pH to decrease. This lowered pH threatens calcifying marine organisms such as corals because it decreases the availability of carbonate ions, an important building block for their skeletons.

Researchers at the University of California, Santa Cruz, Woods Hole Oceanographic Institution and the Water Science Unit of the Scientific Research Center of Yucatan have found that corals living in a naturally acidified reef area have reduced growth rates and are less dense than corals of the same species from a part of the reef with typical seawater.

The ability of corals and other calcifying organisms to acclimate to reduced pH conditions is critical for their survival as the oceans become more acidic. Reduced growth and density of coral skeletons will have important implications for the general health of coral reefs. Decreased density makes the corals more susceptible to erosion and predation, a condition that has serious implications for coral reefs that rely on corals for their structural framework.


  • calcifying corals growing in low pH conditions are more sensitive to erosion
Calcifying corals grow in low pH environments but their skeletons are sensitive to erosion.
Elizabeth D. Crook

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