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| Titel |
Impacts of food availability and pCO2 on planulation, juvenile survival, and calcification of the azooxanthellate scleractinian coral Balanophyllia elegans |
| VerfasserIn |
E. D. Crook, H. Cooper, D. C. Potts, T. Lambert, A. Paytan |
| 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. 11 ; Nr. 10, no. 11 (2013-11-22), S.7599-7608 |
| Datensatznummer |
250085436
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| Publikation (Nr.) |
 copernicus.org/bg-10-7599-2013.pdf |
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| Zusammenfassung |
| Ocean acidification, the assimilation of atmospheric CO2 by the oceans
that decreases the pH and CaCO3 saturation state (Ω) of
seawater, is projected to have severe adverse consequences for calcifying
organisms. While strong evidence suggests calcification by tropical
reef-building corals containing algal symbionts (zooxanthellae) will decline
over the next century, likely responses of azooxanthellate corals to ocean
acidification are less well understood. Because azooxanthellate corals do
not obtain photosynthetic energy from symbionts, they provide a system for
studying the direct effects of acidification on energy available for
calcification. The solitary azooxanthellate orange cup coral Balanophyllia elegans often lives in
low-pH, upwelled waters along the California coast. In an 8-month factorial
experiment, we measured the effects of three pCO2 treatments (410, 770,
and 1220 μatm) and two feeding frequencies (3-day and 21-day intervals)
on "planulation" (larval release) by adult B. elegans, and on the survival, skeletal
growth, and calcification of newly settled juveniles. Planulation rates were
affected by food level but not pCO2. Juvenile mortality was highest
under high pCO2 (1220 μatm) and low food (21-day intervals).
Feeding rate had a greater impact on calcification of B. elegans than pCO2. While
net calcification was positive even at 1220 μatm (~3
times current atmospheric pCO2), overall calcification declined by
~25–45%, and skeletal density declined by ~35–45% as
pCO2 increased from 410 to 1220 μatm. Aragonite
crystal morphology changed at high pCO2, becoming significantly shorter
but not wider at 1220 μatm. We conclude that food abundance is
critical for azooxanthellate coral calcification, and that B. elegans may be partially
protected from adverse consequences of ocean acidification in habitats with
abundant heterotrophic food. |
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