Bleaching susceptibility and mortality of corals are determined by fine-scale differences in symbiont type

Sampayo, E. M., Ridgway, T., Bongaerts, P. and Hoegh-Guldberg, O. (2008) Bleaching susceptibility and mortality of corals are determined by fine-scale differences in symbiont type. Proceedings of the National Academy of Sciences of the United States of America, 105 30: 10444-10449. doi:10.1073/pnas.0708049105


Author Sampayo, E. M.
Ridgway, T.
Bongaerts, P.
Hoegh-Guldberg, O.
Title Bleaching susceptibility and mortality of corals are determined by fine-scale differences in symbiont type
Journal name Proceedings of the National Academy of Sciences of the United States of America   Check publisher's open access policy
ISSN 0027-8424
Publication date 2008-07-29
Sub-type Article (original research)
DOI 10.1073/pnas.0708049105
Open Access Status Not Open Access
Volume 105
Issue 30
Start page 10444
End page 10449
Total pages 6
Editor N. R. Cozzarelli
Place of publication Washington, DC, United States
Publisher National Academy of Sciences
Language eng
Subject C1
960808 Marine Flora, Fauna and Biodiversity
060205 Marine and Estuarine Ecology (incl. Marine Ichthyology)
Abstract Coral bleaching has been identified as one of the major contributors to coral reef decline, and the occurrence of different symbionts determined by broad genetic groupings (clades A–H) is commonly used to explain thermal responses of reef-building corals. By using Stylophora pistillata as a model, we monitored individual tagged colonies in situ over a two-year period and show that fine level genetic variability within clade C is correlated to differences in bleaching susceptibility. Based on denaturing gradient gel electrophoresis of the internal transcribed spacer region 2, visual bleaching assessments, symbiont densities, host protein, and pulse amplitude modulated fluorometry, we show that subcladal types C78 and C8/a are more thermally tolerant than C79 and C35/a, which suffered significant bleaching and postbleaching mortality. Although additional symbiont types were detected during bleaching in colonies harboring types C79 and C35/a, all colonies reverted back to their original symbionts postbleaching. Most importantly, the data propose that the differential mortality of hosts harboring thermally sensitive versus resistant symbionts rather than symbiont shuffling/switching within a single host is responsible for the observed symbiont composition changes of coral communities after bleaching. This study therefore highlights that the use of broad cladal designations may not be suitable to describe differences in bleaching susceptibility, and that differential mortality results in a loss of both symbiont and host genetic diversity and therefore represents an important mechanism in explaining how coral reef communities may respond to changing conditions.
Keyword Climate change
Coral reefs
Symbiodinium
zooxanthellae
Stylophora
Q-Index Code C1
Q-Index Status Confirmed Code

Document type: Journal Article
Sub-type: Article (original research)
Collections: Centre for Marine Studies Publications
2009 Higher Education Research Data Collection
 
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Citation counts: TR Web of Science Citation Count  Cited 160 times in Thomson Reuters Web of Science Article | Citations
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Created: Thu, 16 Apr 2009, 22:54:39 EST by Peter Fogarty on behalf of Centre for Marine Studies