Seawater carbonate chemistry during a Ishigaki Island (Japan) coral reef seasonal observations, 2005

• Main Authors: Kayanne, Hajime, Hata, Hiroshi, Kudo, Setsuko, Yamano, Hiroya, Watanabe, Atsushi, Ikeda, Yutaka, Nozaki, Ken, Kato, Ken, Negishi, Akira, Saito, Hiroshi
• Format: Dataset
• Language: English
• Published: PANGAEA 2005
• Subjects: Alkalinity; total; Aragonite saturation state; Benthos; Bicarbonate ion; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; 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); Infrared gas analyzer (NDIR); Kayanne_etal_05; LICOR quantameter (LI-COR LI-192SA); North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Radiation; photosynthetically active; Reference sample; Rocky-shore community; Salinity; Sampling date; Temperate; Temperature; water; Titration potentiometric; Water quality sensor sonde (H20 sensor; Hydrolab); Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.718250; https://doi.org/10.1594/PANGAEA.718250

Monitoring seawater CO2 for a full year with seasonal observations of community metabolism in Ishigaki Island, Japan, revealed seasonal variation and anomalous values owing to the bleaching event in 1998. The daily average pCO2 showed a seasonal pattern on an annual scale, 280 to 320 ?atm in winter and 360 to 400 ?atm in summer, which was determined primarily by the seasonal change in seawater temperature. By contrast, the range in the diel variation in pCO2, 400 to 500 ?atm in summer 200 to 300 ?atm in winter, was attributed to the seasonal variation in community metabolism: Gross primary production (P g ) and respiration (R) were high in summer and low in winter. During the 1998 bleaching event, although P g and R increased, community excess organic production (E) decreased by three quarters compared with the same month in 1999, when the coral community showed high recovery. This change in metabolism led to large diel range and increased average value of pCO2 levels in the seawater on the reef flat. The decrease in the range and increase in the average value of pCO2 were observed by monitoring the Palau barrier reef flat, where overall mortality of corals occurred after the bleaching. All the metabolic parameters, P g , R, E and calcification (G) were reduced by half after the bleaching, which increased the average pCO2 value by 10 ?atm and decreased its diel range from 200-400 ?atm to 100-200 ?atm. Bleaching and resultant mortality of coral reefs led to degradation of their metabolic performance, and thus resulted in the loss of their active interaction with the carbon cycle.