Coral Carbon Isotope Sensitivity to Growth Rate and Water Depth with Paleo-Sea Level Implications ...

• Main Authors: Linsley, Braddock, Dunbar, Robert B., Dassié, Emilie P., Tangri, Neil, Wu, Henry C., Brenner, Logan, Wellington, Gerard
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2019
• Subjects: Corals; Atmospheric carbon dioxide; Sea level; Paleoceanography; Marine ecology; Pacific; Ocean acidification
• Online Access: https://dx.doi.org/10.7916/d8-1gzc-tj03; https://academiccommons.columbia.edu/doi/10.7916/d8-1gzc-tj03

Reef building corals face an uncertain future due to the accelerating input of anthropogenic CO2 into the surface ocean, ocean acidification and from rising ocean temperatures. Coral skeletal carbon isotope ratios (13C/12) is one potential tool to understand both changes in coral growth processes over time and how corals are responding to the influx of anthropogenic CO2, but interpretation of coral 13C/12C data remains controversial. Here we show for the first time using multi-century long coral cores from a broad region of the South Pacific, that skeletal extension rate and skeletal 13C/12C had a strong inverse correlation that was stable over many centuries. However, our coral results also demonstrate the cessation of this relationship in the mid 20th century as a response to the influx of anthropogenic CO2. This fundamental conundrum suggests some change in the coral calcification process and could be related to coral reef decline in the 20th century. Our results also highlight the fundamental sensitivity ...