Coral Reefs on the Edge? Carbon Chemistry on Inshore Reefs of the Great Barrier Reef

Inshore coral reefs of the Great Barrier Reef (GBR) exhibit disproportionately higher rates of ocean acidification (OA) compared to atmospheric CO₂ increases, with partial pressure of CO₂ (pCO₂) rising 2.5 to 3 times faster than offshore reefs. Over two years, researchers measured total alkalinity and dissolved inorganic carbon at 14 inshore sites, revealing pCO₂ levels consistently higher than atmospheric values, particularly during wet seasons. Despite thermodynamic effects mitigating aragonite saturation (Ωar) reduction in warm months, inshore reefs showed lower Ωar and greater vulnerability to OA due to anthropogenic runoff altering productivity and respiration dynamics. Compared to historical data, inshore pCO₂ increases outpace atmospheric trends, suggesting reduced buffering capacity and heightened susceptibility to environmental stressors.

Uthicke, S., Furnas, M., & Lønborg, C. (2014). Coral Reefs on the Edge? Carbon Chemistry on Inshore Reefs of the Great Barrier Reef. PLoS ONE, 9(10), e109092. https://doi.org/10.1371/journal.pone.0109092