The role of zooxanthellae in the thermal tolerance of corals: a ‘nugget of hope’ for coral reefs in an era of climate change

Proceedings of the Royal Society B: Biological Sciences - Tập 273 Số 1599 - Trang 2305-2312 - 2006
Ray Berkelmans1, Madeleine J. H. van Oppen2
1Cooperative Research Centre for the Great Barrier Reef World Heritage AreaPO Box 772, Townsville 4810, Australia
2Australian Institute of Marine SciencePMB 3 MC, Townsville 4810, Australia

Tóm tắt

The ability of coral reefs to survive the projected increases in temperature due to global warming will depend largely on the ability of corals to adapt or acclimatize to increased temperature extremes over the next few decades. Many coral species are highly sensitive to temperature stress and the number of stress (bleaching) episodes has increased in recent decades. We investigated the acclimatization potential of Acropora millepora , a common and widespread Indo-Pacific hard coral species, through transplantation and experimental manipulation. We show that adult corals, at least in some circumstances, are capable of acquiring increased thermal tolerance and that the increased tolerance is a direct result of a change in the symbiont type dominating their tissues from Symbiodinium type C to D. Our data suggest that the change in symbiont type in our experiment was due to a shuffling of existing types already present in coral tissues, not through exogenous uptake from the environment. The level of increased tolerance gained by the corals changing their dominant symbiont type to D (the most thermally resistant type known) is around 1–1.5 °C. This is the first study to show that thermal acclimatization is causally related to symbiont type and provides new insight into the ecological advantage of corals harbouring mixed algal populations. While this increase is of huge ecological significance for many coral species, in the absence of other mechanisms of thermal acclimatization/adaptation, it may not be sufficient to survive climate change under predicted sea surface temperature scenarios over the next 100 years. However, it may be enough to ‘buy time’ while greenhouse reduction measures are put in place.

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Tài liệu tham khảo

10.1007/s00442-002-1095-1

10.1038/35081151

10.1146/annurev.ecolsys.34.011802.132417

10.1038/430741a

10.1007/s00338-003-0353-y

10.2307/1312064

Buddemeier R.W, 2004, Coral health and disease

10.1016/j.protis.2005.02.004

Done T. Whetton P. Jones R. Berkelmans R. Lough J. Skirving W. & Wooldridge S. 2003 Global climate and coral bleaching on the Great Barrier Reef. Final report to the State of Queensland Greenhouse Taskforce . Brisbane Australia: Queensland government Department of Natural Resources and Mines. (http://www.nrm.qld.gov.au/science/pdf/barrier_reef_report_1.pdf).

10.1007/s00338-003-0364-8

10.4319/lo.2005.50.4.1025

10.1111/j.1365-294X.2004.02230.x

Glynn P.W, 2001, Coral bleaching and mortality in Panama and Ecuador during the 1997–98 El Niño-Southern Oscillation event: spatial/temporal patterns and comparisons with the 1982–1983 event, Bull. Mar. Sci, 69, 79

10.1071/MF99078

10.1038/415601a

IPCC 2001 Technical summary. Climate change 2001: Working Group I: the scientific basis: IPCC Third Assessment Report . Geneva Switzerland: Intergovernmental Panel on Climate Change. (http://www.grida.no/climate/ipcc_tar/).

10.1046/j.1365-3040.1998.00345.x

10.1046/j.1529-8817.2001.01031.x

10.1126/science.1097323

10.1126/science.1095733

10.1029/2000GL011715

Mieog J. C. van Oppen M. J. H Cantin N. C. Stam W. T. & Olsen J. L. In preparation. Large potential for algal symbiont shuffling in reef corals.

10.2307/1297526

10.1007/s00227-004-1427-2

Quinn G& Keough M.J Experimental designs and data analysis for biologists. 2002 Cambridge UK:Cambridge University Press.

10.1038/430742a

10.1073/pnas.92.7.2850

Spalding M.D Ravilious C& Green E.P World atlas of coral reefs. 2001 Berkley CA:University of California Press.

10.1016/S0022-0981(05)80006-1

10.1073/pnas.0402907101

10.1007/s00227-005-0114-2

10.4031/002533202787914160

10.1046/j.1365-294X.2003.01988.x

10.1098/rspb.2001.1733

10.1007/s00338-005-0487-1

Veron J.E.N Corals in space and time: the biogeography and evolution of the scleractinia. 1995 Ithaca NY:Cornell University Press.

Ware J.R, 1997, In Proc. 8th Int. Coral Reef Symp., Panama, 24–29 June 1996, 527