Ocean Acidification has Impacted Coral Growth on the Great Barrier Reef

• Published in: Geophysical Research Letters
• Main Authors: Guo, Weifu, Bokade, Rohit, Cohen, Anne L., Mollica, Nathaniel R., Leung, Muriel, Brainard, Russell E.
• Other Authors: Now at King Abdullah University of Science and Technology, Red Sea Research Center Thuwal Saudi Arabia, Red Sea Research Center (RSRC), Department of Geology and GeophysicsWoods Hole Oceanographic Institution Woods Hole MA USA, Department of Mechanical and Industrial EngineeringNortheastern University Boston MA USA, Massachusetts Institute of Technology-Woods Hole Oceanographic Institution Joint Program in Oceanography Woods Hole MA USA, Department of Physics and Astronomythe University of Pennsylvania Philadelphia PA USA, Pacific Islands Fisheries Science Center, National Oceanic and Atmospheric Administration Honolulu HI USA
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union (AGU) 2020
• Subjects: Pacific; Ocean acidification
• Online Access: http://hdl.handle.net/10754/664990; https://doi.org/10.1029/2019gl086761

Ocean acidification (OA) reduces the concentration of seawater carbonate ions that stony corals need to produce their calcium carbonate skeletons, and is considered a significant threat to the functional integrity of coral reef ecosystems. However, detection and attribution of OA impact on corals in nature are confounded by concurrent environmental changes, including ocean warming. Here we use a numerical model to isolate the effects of OA and temperature, and show that OA alone has caused 13±3% decline in the skeletal density of massive Porites corals on the Great Barrier Reef since 1950. This OA-induced thinning of coral skeletons, also evident in Porites from the South China Sea but not in the central equatorial Pacific, reflects enhanced acidification of reef water relative to the surrounding open ocean. Our finding reinforces concerns that even corals that might survive multiple heatwaves are structurally weakened and increasingly vulnerable to the compounding effects of climate change.