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Permeable coral reef sediment dissolution driven by elevated p CO 2 and pore water advection
Author(s) -
Cyronak T.,
Santos I. R.,
Eyre B. D.
Publication year - 2013
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/grl.50948
Subject(s) - dissolution , coral reef , reef , advection , oceanography , sediment , ocean acidification , carbonate , geology , coral , environmental science , hydrology (agriculture) , seawater , geomorphology , chemistry , physics , geotechnical engineering , organic chemistry , thermodynamics
Ocean acidification (OA) is expected to drive the transition of coral reef ecosystems from net calcium carbonate (CaCO 3 ) precipitating to net dissolving within the next century. Although permeable sediments represent the largest reservoir of CaCO 3 in coral reefs, the dissolution of shallow CaCO 3 sands under future p CO 2 levels has not been measured under natural conditions. In situ, advective chamber incubations under elevated p CO 2 (~800 µatm) shifted the sediments from net precipitating to net dissolving. Pore water advection more than doubled dissolution rates (1.10 g CaCO 3 m −2 d −1 ) when compared to diffusive conditions (0.42 g CaCO 3 m −2 d −1 ). Sediment dissolution could reduce net ecosystem calcification rates of the Heron Island lagoon by 8% within the next century, which is equivalent to a 25% reduction in the global average calcification rate of coral lagoons. The dissolution of CaCO 3 sediments needs to be taken into account in order to address how OA will impact the net accretion of coral reefs under future predicted increases in CO 2 .