Desert Coral Reefs: A possible sink of atmospheric CO2 in a rapidly warming World

Abstract Eddy covariance (EC) measurements of air-sea CO₂ exchange (Net Ecosystem Exchange) over desert fringing coral reefs in the Gulf of Eilat (GoE), Israel show these ecosystems may be net sinks of atmospheric CO₂. This result contrasts with marine productivity models and bulk formula calculations based on for example, water chemistry used to then determine the magnitude and direction of the CO₂ flux. These studies have for more than three decades often concluded that coral reefs are net sources of CO₂ to the atmosphere with only rare cases finding otherwise. Our EC measurements find coral reefs in the GoE sequester 3 to 10 times more CO₂ than other marine and terrestrial ecosystems including tropical rainforests. This highlights the need for further direct measurements of air-sea CO₂ exchanges over coral reefs in different environmental settings and climate regimes so that the role of coral reefs in the global carbon cycle can be accurately quantified.