Carbonate chemistry, community metabolism, PAR, temperature and salinity of One Tree Island reef

• Main Authors: Shaw, Emily, Tilbrook, Bronte, Steven, Andrew D L, Phinn, Stuart R
• Format: Dataset
• Language: English
• Published: PANGAEA 2014
• Subjects: Alkalinity; total; Aragonite saturation state; Benthos; Bicarbonate ion; Calcification/Dissolution; Calcite saturation state; Calculated; 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; Date; DATE/TIME; DEPTH; water; Entire community; EXP; Experiment; Field observation; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Irradiance; LATITUDE; LONGITUDE; Net calcification rate of calcium carbonate; Net photosynthesis rate; OA-ICC; Ocean Acidification International Coordination Centre; One_Tree_Island; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Primary production/Photosynthesis; Rocky-shore community; Salinity; Site; South Pacific; Temperate; Temperature; Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.835109; https://doi.org/10.1594/PANGAEA.835109

There are few in situ studies showing how net community calcification (Gnet) of coral reefs is related to carbonate chemistry, and the studies to date have demonstrated different predicted rates of change. In this study, we measured net community production (Pnet), Gnet, and carbonate chemistry of a reef flat at One Tree Island, Great Barrier Reef. Diurnal pCO2 variability of 289-724 µatm was driven primarily by photosynthesis and respiration. The reef flat was found to be net autotrophic, with daily production of ~ 35 mmol C/m**2/d and net calcification of ~ 33 mmol C/m**2/d . Gnet was strongly related to Pnet, which drove a hysteresis pattern in the relationship between Gnet and aragonite saturation state (Omega ar). Although Pnet was the main driver of Gnet, Omega ar was still an important factor, where 95% of the variance in Gnet could be described by Pnet and Omega ar. Based on the observed in situ relationship, Gnet would be expected to reach zero when Omega ar is 2.5. It is unknown what proportion of a decline in Gnet would be through reduced calcification and what would occur through increased dissolution, but the results here support predictions that overall calcium carbonate production will decline in coral reefs as a result of ocean acidification.