The aragonite saturation state is commonly used to track ocean acidification because it is a measure of carbonate ion concentration, which indicates the availability of the calcium carbonate that is widely used by marine calcifiers, from lobsters to clams to starfish. Aragonite itself is the building block of stony corals that are the primary framework and habitat builders of coral reef ecosystems. Corals and other calcifiers are most likely to survive and reproduce when the aragonite saturation state is greater than 4. Saturation above 3.5 is adequate; above 3 is considered marginal, with growth difficult. When the saturation state falls below 3, these organisms are in danger. Below 1, reefs, shells, and other aragonite structures begin to dissolve entirely.

2010 Projected Ocean Acidification: Suitability for Coral Reefs

2020 Projected Ocean Acidification: Suitability for Coral Reefs

2030 Projected Ocean Acidification: Suitability for Coral Reefs

2040 Projected Ocean Acidification: Suitability for Coral Reefs

2050 Projected Ocean Acidification: Suitability for Coral Reefs

2060 Projected Ocean Acidification: Suitability for Coral Reefs

2070 Projected Ocean Acidification: Suitability for Coral Reefs

2080 Projected Ocean Acidification: Suitability for Coral Reefs

2090 Projected Ocean Acidification: Suitability for Coral Reefs

2099 Projected Ocean Acidification: Suitability for Coral Reefs

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