Contrasting calcification responses to ocean acidification between two reef foraminifers harboring different algal symbionts
Article first published online: 6 OCT 2011
Copyright 2011 by the American Geophysical Union.
Geophysical Research Letters
Volume 38, Issue 19, October 2011
How to Cite
2011), Contrasting calcification responses to ocean acidification between two reef foraminifers harboring different algal symbionts, Geophys. Res. Lett., 38, L19601, doi:10.1029/2011GL048501., , , , , , , , and (
- Issue published online: 6 OCT 2011
- Article first published online: 6 OCT 2011
- Manuscript Accepted: 2 SEP 2011
- Manuscript Revised: 30 AUG 2011
- Manuscript Received: 12 JUN 2011
- culture experiment;
- ocean acidification
 Ocean acidification, which like global warming is an outcome of anthropogenic CO2 emissions, severely impacts marine calcifying organisms, especially those living in coral reef ecosystems. However, knowledge about the responses of reef calcifiers to ocean acidification is quite limited, although coral responses are known to be generally negative. In a culture experiment with two algal symbiont-bearing, reef-dwelling foraminifers, Amphisorus kudakajimensis and Calcarina gaudichaudii, in seawater under five different pCO2 conditions, 245, 375, 588, 763 and 907 μatm, maintained with a precise pCO2-controlling technique, net calcification of A. kudakajimensis was reduced under higher pCO2, whereas calcification of C. gaudichaudii generally increased with increased pCO2. In another culture experiment conducted in seawater in which bicarbonate ion concentrations were varied under a constant carbonate ion concentration, calcification was not significantly different between treatments in Amphisorus hemprichii, a species closely related to A. kudakajimensis, or in C. gaudichaudii. From these results, we concluded that carbonate ion and CO2 were the carbonate species that most affected growth of Amphisorus and Calcarina, respectively. The opposite responses of these two foraminifer genera probably reflect different sensitivities to these carbonate species, which may be due to their different symbiotic algae.