To identify the underlying biophysical mechanism by which ocean acidification impairs reef coral calcification.
Reanalyzed existing experimental datasets assessing the relative effects of seawater pH, carbonate, bicarbonate, aragonite saturation state, total alkalinity, and dissolved inorganic carbon on coral calcification.
Evaluated diffusion kinetics and proton (H+) transport dynamics through the coral diffusive boundary layer across varying seawater proton concentrations.
Identified diffusion limitation of net H+ transport through the diffusive boundary layer as the primary mechanistic cause of reduced calcification.
Elevated seawater [H+] suppresses the concentration gradient required for proton efflux from the coral tissue, directly inhibiting calcium carbonate deposition.