Stanley highlights the dual significance of our findings: a confirmation of his naked coral hypothesis (1) and a plausible explanation for the enigma of discontinuity in the geological record of coral reefs (2).
Stanley uses our findings to suggest that scleractinians and noncalcifying species that are typically classified as a different order (such as corallimorpharians) are probably one clade. This is supported also by phylogenetic studies using molecular tools (3), demonstrating that a clade of scleractinians is more closely related to noncalcifying corallimorpharia than to another clade of scleractinians.
Stanley criticizes our study for using two Mediterranean coral species that he refers to as “not representative.” Indeed, these are not classic reef-building corals; however, we doubt there is a definition of a “typical coral.” The evolution and basic physiology of the studied species are indistinguishable from that of tropical reef-building corals (4, 5). Over 98% of the colonies of the studied species are symbiotic, suffering reduced growth, lower competitive abilities, and reduced physiological state when losing their endosymbiotic dinoflagellates (bleach) (4). Hence, there is no reason to suspect that they have a different photosymbiosis, as Stanley proposed. We chose the studied species for their relatively slow calcification rate, a preferred condition for our decalcification experiment.
We share Stanley’s concern that our findings might be misinterpreted by the reader, as the title suggests “survival.” The last sentence in our paper, however, clearly states that while we discovered physiological refugia for corals under acidified conditions, coral reefs and their services will be lost. Corals without carbonate skeleton do not provide protection from predators to both the coral host and the numerous species that are associated with it. So even if corals survive acidification, reefs will not.
Maoz Fine
Faculty of Life Sciences
Bar-Ilan University
Ramat-Gan 52900, Israel
The Interuniversity Institute for Marine Sciences
Eilat 88103, Israel
Dan Tchernov
Department of Evolution, Systematics and Ecology
The Hebrew University of Jerusalem
Givat Ram, Jerusalem 91904, Israel
The Interuniversity Institute for Marine Sciences
Eilat 88103, Israel
References
1. G. D. Stanley Jr., D. G. Fautin, Science 291, 1913 (2001).
2. G. D. Stanley Jr., Earth Sci. Rev. 60, 195 (2003).
3. M. Medina, A. G. Collins, T. L. Takaoka, J. V. Kuehl, J. L. Boore, Proc. Natl. Acad. Sci. U.S.A. 103, 11814 (2006).
4. M. Fine, U. Oren, Y. Loya, Mar. Ecol. Prog. Ser. 234, 119 (2002).
5. M. Fine, H. Zibrowius, Y. Loya, Mar. Biol. 138, 1195 (2001).
Fine M. & Tchernov D., 2007. Ocean acidification and scleractinian corals. Science 317(5841):1032c. Article.
Technorati Tags: biological response, calcification, coral, paleo
