Seawater carbonate chemistry and community calcification during Reunion Island coral reef community study, 2007

• Main Authors: Taddei, Dorothée, Bucas, G, Clavier, Jacques, Cuet, Pascale, Frouin, P
• Format: Dataset
• Language: English
• Published: PANGAEA 2007
• Subjects: Alkalinity; potentiometric; 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); Indian Ocean; OA-ICC; Ocean Acidification International Coordination Centre; PAR sensor LI-1400; LI-COR Inc.; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Electrode; Radiation; photosynthetically active; Salinity; Sample ID; Soft-bottom community; Taddei_etal_07; Temperature; water; Tropical; YSI 6920 salinity/conductivity/temperature meter; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.721964; https://doi.org/10.1594/PANGAEA.721964

To assess the contribution of soft-bottoms to the carbon cycle in coral reefs, the net community production (p) was measured in winter at 3 stations on La Saline inner reef flat (Reunion Island). Changes in pH and total alkalinity at different irradiances (I) were assessed using benthic chambers (0.2 m2) during a 1-h incubation. Mean grain size, the silt and clay load and chlorophyll a content of the sediments were analysed in each chamber. Daily community production (P), gross community production (Pg) and community respiration (R) were estimated from p-I curves and daily irradiance variations (PAR, 400-700 nm). Sediment characteristics and chlorophyll a contents did not differ between the three sites, except for the silt and clay fraction at one station. R being higher than Pg (84.88 ± 7.36 and -62.29 ± 3.34 mmolC m-2 d-1 respectively), P value reached 22.59 ± 5.66 mmolC m-2 d-1. The sediments were therefore heterotrophic with a mean Pg/R lower than 1 (0.74 ± 0.05) and appear to be a carbon source. Our data suggested the importance of the degradation process in the functioning of near-reef sediments.