Next-century ocean acidification and warming both reduce calcification rate, but only acidification alters skeletal morphology of reef-building coral Siderastrea siderea
Horvath, K.M.; Castillo, K.D.; Armstrong, P.; Westfield, I.T.; Courtney, T.; Ries, J.B. (2016). Next-century ocean acidification and warming both reduce calcification rate, but only acidification alters skeletal morphology of reef-building coral Siderastrea siderea. NPG Scientific Reports 6(29613): 12 pp. http://dx.doi.org/10.1038/srep29613
In: Scientific Reports (Nature Publishing Group). Nature Publishing Group: London. ISSN 2045-2322; e-ISSN 2045-2322, more
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Authors | | Top |
- Horvath, K.M.
- Castillo, K.D.
- Armstrong, P.
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- Westfield, I.T.
- Courtney, T.
- Ries, J.B.
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Abstract |
Atmospheric pCO(2) is predicted to rise from 400 to 900 ppm by year 2100, causing seawater temperature to increase by 1-4 degrees C and pH to decrease by 0.1-0.3. Sixty-day experiments were conducted to investigate the independent and combined impacts of acidification (pCO(2) = 424-426, 888-940 ppm-v) and warming (T = 28, 32 degrees C) on calcification rate and skeletal morphology of the abundant and widespread Caribbean reef-building scleractinian coral Siderastrea siderea. Hierarchical linear mixed-effects modelling reveals that coral calcification rate was negatively impacted by both warming and acidification, with their combined effects yielding the most deleterious impact. Negative effects of warming (32 degrees C/424 ppm-v) and high-temperature acidification (32 degrees C/940 ppm-v) on calcification rate were apparent across both 30-day intervals of the experiment, while effects of low-temperature acidification (28 degrees C/888 ppm-v) were not apparent until the second 30-day interval-indicating delayed onset of acidification effects at lower temperatures. Notably, two measures of coral skeletal morphology-corallite height and corallite infilling-were negatively impacted by next-century acidification, but not by next-century warming. Therefore, while next-century ocean acidification and warming will reduce the rate at which corals build their skeletons, next-century acidification will also modify the morphology and, potentially, function of coral skeletons. |
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