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Dependence of calcification on light and carbonate ion concentration for the hermatypic coral Porites compressa
- Source :
- Scopus-Elsevier
- Publication Year :
- 2001
- Publisher :
- Inter-Research Science Center, 2001.
-
Abstract
- Temperature, light and aragonite saturation state of seawater are important determinants of the global distribution of coral reefs. Saturation state of surface seawater is decreasing in response to increases in atmospheric pCO 2 , causing concern for a global reduction in the rates ol reef accretion. In this study we address the influences of light and saturation state on skeletal growth of the hermatypic coral Porites compressa. We conducted 2 experiments using coral nubbins; one in a controlled laboratory with Biosphere 2 ocean water and the other in the 711 m 2 Biosphere 2 ocean itself. The laboratory experiment consisted of 3 light treatments (PAR = 698, 150, 81 μmol photons m -2 s -1 ) and 2 chemical treatments (pCO 2 = 199 μatm, Ω = 5.05, CO 3 2- = 355 μmol kg -1 ; and pCO 2 = 448 μatm, Ω = 2.48, CO 3 2- = 183 μmol kg -1 ). In the Biosphere 2 ocean, coral nubbins were deployed at 4 depths (6, 4, 2 and 0.5 m) which corresponded to different light conditions (PAR from 2.7 to 29.5 mol photons m -2 d -1 ) during 3 different chemical states, mimicking the conditions of the Last Glacial Maximum (LGM), the present day and the year 2100 (Y2100). Calcification rate changed with light following the typical hyperbolic tangent function. Calcification rate was positively correlated with saturation state, which ranged from 5 (LGM) to 2.4 (Y2100). From the glacial experimental conditions (Ω = 5.05, pCO 2 = 186) to those of the future (Ω = 2.25, pCO 2 = 641), calcification dropped by 30%; from present day conditions (Ω = 3.64, pCO 2 = 336) to those of the future, calcification dropped by 11%, This decrease in calcification rate occurred at all light levels, indicating that rising CO 2 will impact corals living at all depths.
- Subjects :
- geography
geography.geographical_feature_category
Ecology
biology
Porites compressa
Aragonite
Coral
Hermatypic coral
Coral reef
Aquatic Science
Stylophora pistillata
engineering.material
biology.organism_classification
Oceanography
engineering
Seawater
Saturation (chemistry)
Ecology, Evolution, Behavior and Systematics
Subjects
Details
- ISSN :
- 16161599 and 01718630
- Volume :
- 220
- Database :
- OpenAIRE
- Journal :
- Marine Ecology Progress Series
- Accession number :
- edsair.doi.dedup.....761f73f3c70ce870b91f83311e747701
- Full Text :
- https://doi.org/10.3354/meps220153