Permeable coral reef sediment dissolution driven by elevated pCO2 and pore water advection

• Main Authors: Cyronak, Tyler, Santos, Isaac R, Eyre, Bradley D
• Format: Dataset
• Language: English
• Published: PANGAEA 2013
• Subjects: Alkalinity; total; flux; Aragonite saturation state; Benthos; Bicarbonate ion; Bottles or small containers/Aquaria (<20 L); Calcification/Dissolution; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Entire community; Field experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Identification; OA-ICC; Ocean Acidification International Coordination Centre; Oxygen; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Potentiometric; Potentiometric titration; Rocky-shore community; Salinity; South Pacific; Temperature; water; Treatment; Tropical; Heron Island; Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.833970; https://doi.org/10.1594/PANGAEA.833970

Ocean acidification (OA) is expected to drive the transition of coral reef ecosystems from net calcium carbonate (CaCO3) precipitating to net dissolving within the next century. Although permeable sediments represent the largest reservoir of CaCO3 in coral reefs, the dissolution of shallow CaCO3 sands under future pCO2 levels has not been measured under natural conditions. In situ, advective chamber incubations under elevated pCO2 (~800 µatm) shifted the sediments from net precipitating to net dissolving. Pore water advection more than doubled dissolution rates (1.10 g CaCO3/m**2/day) when compared to diffusive conditions (0.42 g CaCO3/m**2 /day). 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 CaCO3 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 CO2.