Light‐driven dynamics between calcification and production in functionally diverse coral reef calcifiers

Coral reef metabolism underpins ecosystem function and is defined by the processes of photosynthesis, respiration, calcification, calcium carbonate dissolution. However, relationships between these physiological at organismal level their interactions with light remain unclear. We examined metabolic rates across a range photosynthesising calcifiers in Caribbean: scleractinian corals Acropora cervicornis, Orbicella faveolata, Porites astreoides, Siderastrea siderea, crustose coralline algae (CCA) under varying natural conditions. Net photosynthesis calcification showed parabolic response to all species, differences among massive corals, branching CCA that reflect relative functional roles on reef. At night, organisms were net respiring, most calcifying, although some incubations demonstrated instances (CaCO3) Peak light-saturation (maximum calcification) average dark (respiration positively correlated species. Interspecies indicate are linked energy production calcifying organisms. The species-specific ratios varied over diurnal cycle. dynamic nature calcification/photosynthesis cycle questions use this metric as an indicator for health scale unless temporal variability accounted for, new proposed. complex light-driven dynamics coral more comprehensive understanding needed predicting future impacts global change.