Introduction to Ocean
Acidification

Introduction to Acidification's Effects on Coral

Key Physiological Characteristics of Coral

Chemistry of Coral Calcification

How is Coral Calcification Affected by Acidification?

Acidification's Effects on Other Calcifying Organisms

Abiotic Controls: Environmental Control

Zooxanthellae provide considerable amounts of energy to coral, and thus any environmental variable which impacts zooxanthellae productivity will also impact coral calcification (Allemand et al., 2011).  A well-understood example of this is called “light-enhanced calcification” (Allemand et al., 2011).  Under light-enhanced calcification, coral containing zooxanthellae calcify at significantly higher rates when in light than when in dark.  However, this theory has been challenged, with some arguing that calcification is what spurs photosynthesis, and others arguing that reduced photosynthesis inhibits calcification due to factors other than energy production (Allemand et al., 2011).  Whatever the mechanism, light does appear to have an effect on calcification, and thus any environmental factor that can affect light (such as turbidity), can also impact calcification (Allemand et al., 2011).

Other environmental factors that have an impact on calcification include temperature, nutrition, the concentration of CO2 and salinity.  We will investigate the effects of CO2 in the next section.