Seawater carbonate chemistry and calcification rate during mesocosm experiments with coral Montipora capitata, 2008

• Main Authors: Jokiel, Paul L, Rodgers, Ku'ulei, Kuffner, Ilsa B, Andersson, Andreas J, Cox, E F, Mackenzie, Fred T
• Format: Dataset
• Language: English
• Published: PANGAEA 2008
• Subjects: Alkalinity; total; Animalia; Aragonite saturation state; Benthic animals; Benthos; Bicarbonate ion; Buoyant weighing technique (Davies; 1989); Calcification/Dissolution; Calcification rate of calcium carbonate; Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Cnidaria; Coast and continental shelf; Containers and aquaria (20-1000 L or < 1 m**2); EPOCA; EUR-OCEANS; European network of excellence for Ocean Ecosystems Analysis; European Project on Ocean Acidification; Experimental treatment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Laboratory experiment; Measured; Montipora capitata; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Salinity; Single species; Temperature; water; Timeslice; Tropical; Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.763898; https://doi.org/10.1594/PANGAEA.763898

A long-term (10 months) controlled experiment was conducted to test the impact of increased partial pressure of carbon dioxide (pCO2) on common calcifying coral reef organisms. The experiment was conducted in replicate continuous flow coral reef mesocosms flushed with unfiltered sea water from Kaneohe Bay, Oahu, Hawaii. Mesocosms were located in full sunlight and experienced diurnal and seasonal fluctuations in temperature and sea water chemistry characteristic of the adjacent reef flat. Treatment mesocosms were manipulated to simulate an increase in pCO2 to levels expected in this century [midday pCO2 levels exceeding control mesocosms by 365 ± 130 µatm (mean ± sd)]. Acidification had a profound impact on the development and growth of crustose coralline algae (CCA) populations. During the experiment, CCA developed 25% cover in the control mesocosms and only 4% in the acidified mesocosms, representing an 86% relative reduction. Free-living associations of CCA known as rhodoliths living in the control mesocosms grew at a rate of 0.6 g buoyant weight per year while those in the acidified experimental treatment decreased in weight at a rate of 0.9 g buoyant weight per year, representing a 250% difference. CCA play an important role in the growth and stabilization of carbonate reefs, so future changes of this magnitude could greatly impact coral reefs throughout the world. Coral calcification decreased between 15% and 20% under acidified conditions. Linear extension decreased by 14% under acidified conditions in one experiment. Larvae of the coral Pocillopora damicornis were able to recruit under the acidified conditions. In addition, there was no significant difference in production of gametes by the coral Montipora capitata after 6 months of exposure to the treatments.