In Situ effects of low pH and elevated HCO3 on juvenile massive Porites spp. in Moorea, French Polynesia, supplement to: Wall, Christopher B; Edmunds, Peter J (2013): In Situ Effects of Low pH and Elevated HCO3- on Juvenile Massive Porites spp. in Moorea, French Polynesia. Biological Bulletin, 225, 92–101

• Main Authors: Wall, Christopher B, Edmunds, Peter J
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2013
• Subjects: Animalia; Benthic animals; Benthos; Bottles or small containers/Aquaria <20 L; Calcification/Dissolution; Cnidaria; Coast and continental shelf; Field experiment; Porites sp.; Respiration; Single species; South Pacific; Tropical; Species; Figure; Date; Treatment; Replicate; Respiration rate, oxygen; Calcification rate of calcium carbonate; Metabolic expenditure; pH; Partial pressure of carbon dioxide water at sea surface temperature wet air; Alkalinity, total; Bicarbonate ion; Carbonate ion; Carbon, inorganic, dissolved; Aragonite saturation state; Salinity; Temperature, water; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Calcite saturation state; Potentiometric; Calculated using seacarb; Potentiometric titration; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Pacific; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.833913; https://doi.pangaea.de/10.1594/PANGAEA.833913

Juvenile colonies of massive Porites spp. were exposed to manipulated pH and bicarbonate ([HCO3-]) in situ to test the hypothesis that ocean acidification (OA) does not affect respiration and calcification. Incubations lasted 28 h and exposed corals to ambient temperature and light with ecologically relevant water motion. Three treatments were applied: (1) ambient conditions of pH 8.04 and 1751 µmol HCO3- kg(-1) (Treatment 1), (2) pCO2-induced ocean acidification of pH 7.73 and 2011 µmol HCO3- kg(-1) (Treatment 2), and (3) pCO2 and HCO3--enriched seawater of pH 7.69 and 2730 µmol HCO3- kg(-1) (Treatment 3). The third treatment providing elevated [HCO3-] was used to test for stimulatory effects of dissolved inorganic carbon on calcification under low pH and low saturation of aragonite (Omega arag), but it does not reflect conditions expected to occur under CO2-driven OA. Calcification of juvenile massive Porites spp. was affected by treatments, with an 81% elevation in Treatment 3 versus Treatment 1, but no difference between Treatments 1 and 2; respiration and the metabolic expenditure concurrent with calcification remained unaffected. These findings indicate that juvenile massive Porites spp. are resistant to short exposures to OA in situ, and separately, that they can increase calcification at low pH and low Omega arag if [HCO3-] is elevated. Juvenile Porites spp. may therefore be limited by dissolved inorganic carbon under ambient pCO2 conditions : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne et al, 2014) 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). The date of carbonate chemistry calculation is 2014-07-09.