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| Titel |
Dynamics of seawater carbonate chemistry, production, and calcification of a coral reef flat, central Great Barrier Reef |
| VerfasserIn |
R. Albright, C. Langdon, K. R. N. Anthony |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 10 ; Nr. 10, no. 10 (2013-10-28), S.6747-6758 |
| Datensatznummer |
250085379
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| Publikation (Nr.) |
 copernicus.org/bg-10-6747-2013.pdf |
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| Zusammenfassung |
| Ocean acidification is projected to shift coral reefs from a state of net
accretion to one of net dissolution this century. Presently, our ability to
predict global-scale changes to coral reef calcification is limited by
insufficient data relating seawater carbonate chemistry parameters to
in situ rates of reef calcification. Here, we investigate diel and
seasonal trends in carbonate chemistry of the Davies Reef flat in the central
Great Barrier Reef and relate these trends to benthic carbon fluxes by
quantifying net ecosystem calcification (nec) and net community production
(ncp). Results show that seawater carbonate chemistry of the Davies Reef flat
is highly variable over both diel and seasonal cycles. pH (total scale)
ranged from 7.92 to 8.17, pCO2 ranged from 272 to 542 μatm,
and aragonite saturation state (Ωarag) ranged from 2.9 to
4.1. Diel cycles in carbonate chemistry were primarily driven by ncp, and
warming explained 35% and 47% of the seasonal shifts in pCO2 and
pH, respectively. Daytime ncp averaged
37 ± 19 mmol C m−2 h−1 in summer and
33 ± 13 mmol C m−2 h−1 in winter; nighttime ncp averaged
−30 ± 25 and −7 ± 6 mmol C m−2 h−1 in summer
and winter, respectively. Daytime nec averaged
11 ± 4 mmol CaCO3 m−2 h−1 in summer and
8 ± 3 mmol CaCO3 m−2 h−1 in winter, whereas
nighttime nec averaged 2 ± 4 mmol and
−1 ± 3 mmol CaCO3 m−2 h−1 in summer and winter,
respectively. Net ecosystem calcification was highly sensitive to changes in
Ωarag for both seasons, indicating that relatively small
shifts in Ωarag may drive measurable shifts in calcification
rates, and hence carbon budgets, of coral reefs throughout the year. |
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