Community production modulates coral reef pH and the sensitivity of ecosystem calcification to ocean acidification
DeCarlo, Thomas M.
Cohen, Anne L.
Wong, George T. F.
Lentz, Steven J.
Davis, Kristen A.
Shamberger, Kathryn E. F.
Lohmann, George P.
MetadataShow full item record
Coral reefs are built of calcium carbonate (CaCO3) produced biogenically by a diversity of calcifying plants, animals, and microbes. As the ocean warms and acidifies, there is mounting concern that declining calcification rates could shift coral reef CaCO3 budgets from net accretion to net dissolution. We quantified net ecosystem calcification (NEC) and production (NEP) on Dongsha Atoll, northern South China Sea, over a 2 week period that included a transient bleaching event. Peak daytime pH on the wide, shallow reef flat during the nonbleaching period was ∼8.5, significantly elevated above that of the surrounding open ocean (∼8.0–8.1) as a consequence of daytime NEP (up to 112 mmol C m−2 h−1). Diurnal-averaged NEC was 390 ± 90 mmol CaCO3 m−2 d−1, higher than any other coral reef studied to date despite comparable calcifier cover (25%) and relatively high fleshy algal cover (19%). Coral bleaching linked to elevated temperatures significantly reduced daytime NEP by 29 mmol C m−2 h−1. pH on the reef flat declined by 0.2 units, causing a 40% reduction in NEC in the absence of pH changes in the surrounding open ocean. Our findings highlight the interactive relationship between carbonate chemistry of coral reef ecosystems and ecosystem production and calcification rates, which are in turn impacted by ocean warming. As open-ocean waters bathing coral reefs warm and acidify over the 21st century, the health and composition of reef benthic communities will play a major role in determining on-reef conditions that will in turn dictate the ecosystem response to climate change.
Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 745–761, doi:10.1002/2016JC012326.
Suggested CitationJournal of Geophysical Research: Oceans 122 (2017): 745–761
Showing items related by title, author, creator and subject.
Shamberger, Kathryn E. F.; Lentz, Steven J.; Cohen, Anne L. (John Wiley & Sons, 2017-10-09)Laboratory‐based CO2 experiments and studies of naturally low pH coral reef ecosystems reveal negative impacts of ocean acidification on the calcifying communities that build coral reefs. Conversely, in Palau's low pH ...
Reduced calcification and lack of acclimatization by coral colonies growing in areas of persistent natural acidification Crook, Elizabeth D.; Cohen, Anne L.; Rebolledo-Vieyra, Mario; Hernandez, Laura; Paytan, Adina (2013-05)As the surface ocean equilibrates with rising atmospheric CO2, the pH of surface seawater is decreasing with potentially negative impacts on coral calcification. A critical question is whether corals will be able to adapt ...
Morphological and compositional changes in the skeletons of new coral recruits reared in acidified seawater : insights into the biomineralization response to ocean acidification Cohen, Anne L.; McCorkle, Daniel C.; de Putron, Samantha J.; Gaetani, Glenn A.; Rose, Kathryn A. (American Geophysical Union, 2009-07-24)We reared primary polyps (new recruits) of the common Atlantic golf ball coral Favia fragum for 8 days at 25°C in seawater with aragonite saturation states ranging from ambient (Ω = 3.71) to strongly undersaturated (Ω = ...