Seawater carbonate chemistry and calcification during tropical reef studies at Moorea (French Polynesia), 1996

• Main Authors: Gattuso, Jean-Pierre, Pichon, Michel, Delesalle, Bruno, Canon, C, Frankignoulle, Michel
• Format: Dataset
• Language: English
• Published: PANGAEA 1996
• Subjects: Alkalinity; total; Alkalinity anomaly technique (Smith and Key; 1975); Aragonite saturation state; Benthos; Bicarbonate ion; Calcification/Dissolution; Calcification rate of calcium carbonate; Calcite saturation state; Calculated; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; DATE/TIME; Entire community; EPOCA; EUR-OCEANS; European network of excellence for Ocean Ecosystems Analysis; European Project on Ocean Acidification; EXP; Experiment; Field observation; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gattuso_etal_96M; LICOR quantameter (LI-COR LI-192SA); Moorea (French Polynesia); OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Radiation; photosynthetically active; Salinity; Soft-bottom community; South Pacific; Temperature; water; Thermistor; Titration potentiometric (Metler-Toledo); Tropical; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.717486; https://doi.org/10.1594/PANGAEA.717486

Community metabolism was investigated using a Lagrangian flow respirometry technique on 2 reef flats at Moorea (French Polynesia) during austral winter and Yonge Reef (Great Barrier Reef) during austral summer. The data were used to estimate related air-sea CO2 disequilibrium. A sine function did not satisfactorily model the diel light curves and overestimated the metabolic parameters. The ranges of community gross primary production and respiration (Pg and R; 9 to 15 g C m-2 d-1) were within the range previously reported for reef flats, and community net calcification (G; 19 to 25 g CaCO3 m-2 d-1) was higher than the 'standard' range. The molar ratio of organic to inorganic carbon uptake was 6:1 for both sites. The reef flat at Moorea displayed a higher rate of organic production and a lower rate of calcification compared to previous measurements carried out during austral summer. The approximate uncertainty of the daily metabolic parameters was estimated using a procedure based on a Monte Carlo simulation. The standard errors of Pg,R and Pg/R expressed as a percentage of the mean are lower than 3% but are comparatively larger for E, the excess production (6 to 78%). The daily air-sea CO2 flux (FCO2) was positive throughout the field experiments, indicating that the reef flats at Moorea and Yonge Reef released CO2 to the atmosphere at the time of measurement. FCO2 decreased as a function of increasing daily irradiance.