Coral reef calcification: carbonate,bicarbonate and proton flux under conditions of increasing ocean acidification

Data on calcification rate of coral and crustose coralline algae were used to test the proton flux model of calcification. There was a significant correlation between calcification (G) and the ratio of dissolved inorganic carbon (DIC) to proton concentration (DIC] : H⁺] ratio). The ratio is tightly correlated with CO₃²⁻] and with aragonite saturation state (Ω_a). An argument is presented that correlation does not prove cause and effect, and that Ω_a and CO₃²⁻] have no basic physiological meaning on coral reefs other than a correlation with DIC] : H⁺] ratio, which is the driver of G.