Seawater carbonate chemistry and community calcification during Reunion Island coral reef community study, 2006

• Main Author: Taddei, Dorothée
• Format: Dataset
• Language: English
• Published: PANGAEA 2006
• 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; DEPTH; water; Entire community; EPOCA; EUR-OCEANS; European network of excellence for Ocean Ecosystems Analysis; European Project on Ocean Acidification; Event label; Field observation; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Identification; Indian Ocean; OBSE; Observation; PAR sensor LI-1400; LI-COR Inc.; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; pH meter (Orion 940); Radiation; photosynthetically active; Salinity; Salinometer (Yeo-Cap Mark IV); Site; Soft-bottom community; Taddei_06-S1; Taddei_06-S2; Taddei_06-S3; Taddei_06-S4; Temperature; Indian; Orion; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.727530; https://doi.org/10.1594/PANGAEA.727530

Coral reefs are very productive ecosystems. Soft-sediment plays generally a role in storing place, in transforming and in producing of matter, and therefore it could play a key role in coral reefs ecosystems. The goal of this study was to evaluate the role of soft-bottom compartment during the transfer of matter and energy in the reef of La Saline (Reunion Island). Three main lines of research were developed: the physicochemical characterisation of studied site, the metabolism of soft bottom in view to estimate the trophic production and its status and finally, the characterisation of biological component by the study of macrobentos and megabentos (i.e. Holothurians). A limited disturbance was detected by physicochemical data although locally enrichment of freshwater by nutrients (nitrates+nitrites+silicates) were measured (reef back hollow of Planch'Alize and Grand Trou d'Eau). At the reef scale (9 stations and 2 seasons), the soft-sediment was found heterotrophic (net production = 31.6, respiration R = 109.6, gross production Pg = 77.9 mmolC m-2 d-1 et PgR = 0.7). Opposite to the two holothurians studied population Holothuria atra et H. leucospilota, macrobenthos (> 1 mm) did not constitute a major group in the food web (134 taxa, with a mean of 32.86 individuals per 0.2 m-2 et 0.059 gPS 0.2m-2. compared to Echinoderm biomass that could reach 7.92 gPS m-2. At the station scale, spatial heterogeneity of metabolism was in agreement with the physicochemical characteristics of environment reflecting the double influence of both ocean and continent (freshwater enrichment). The most productive and heterotrophic stations were located in the reef back hollow where the oceanic influence was the lowest. Finally, macrofauna was under hydrodynamic influence although holothurians are growing in the most productive area. The soft-bottom sediment played a key role in filtrating organic matter provided from the back reef. This mechanism was deeply influenced by the high hydrodynamism (narrow reef and low water level), ...