Seawater carbonate chemistry and community calcification during Reunion Island coral reef community study, 2007, supplement to: Taddei, Dorothée; Bucas, G; Clavier, Jacques; Cuet, Pascale; Frouin, P (2007): Carbon fluxes at the water-sediment interface in Reunion Island fringing reef. Western Indian Ocean Journal of Marine Science, 6(2), 137-146

• Main Authors: Taddei, Dorothée, Bucas, G, Clavier, Jacques, Cuet, Pascale, Frouin, P
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2007
• Subjects: Benthos; Calcification/Dissolution; Coast and continental shelf; Entire community; Field observation; Indian Ocean; Soft-bottom community; Tropical; DATE/TIME; Sample ID; Salinity; Temperature, water; Radiation, photosynthetically active; Carbonate system computation flag; pH; Alkalinity, total; Carbon, inorganic, dissolved; Carbon dioxide; Carbonate ion; Bicarbonate ion; Partial pressure of carbon dioxide water at sea surface temperature wet air; Fugacity of carbon dioxide water at sea surface temperature wet air; Aragonite saturation state; Calcite saturation state; Calcification rate of calcium carbonate; Experiment; YSI 6920 salinity/conductivity/temperature meter; PAR sensor LI-1400, LI-COR Inc.; Calculated using seacarb after Nisumaa et al. 2010; pH, Electrode; Alkalinity, potentiometric; Calculated; Alkalinity anomaly technique Smith and Key, 1975; European network of excellence for Ocean Ecosystems Analysis EUR-OCEANS; European Project on Ocean Acidification EPOCA; Ocean Acidification International Coordination Centre OA-ICC; Indian; Inner Reef; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.721964; https://doi.pangaea.de/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. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne and Gattuso, 2011) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI).