Exploring the basis of thermotolerance in the reef coral Goniastrea aspera

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 242:119-129 (2002) - doi:10.3354/meps242119 Exploring the basis of thermotolerance in the reef coral Goniastrea aspera B. E. Brown1,*, C. A. Downs2, R. P. Dunne1, S. W. Gibb3 1Department of Marine Sciences and Coastal Management, University of Newcastle, Newcastle upon Tyne NE1 7RU, United Kingdom 2EnVirtue Biotechnologies Inc, 2255 Ygnacio Valley Road, Suite H-1 Walnut Creek, California 94598, USA 3Environmental Research Institute, The North Highland College, UHI Millennium Institute, Castle Street, Thurso, Caithness KW14 7JD, Scotland, United Kingdom *E-mail: 101515.1267@compuserve.com ABSTRACT: The shallow-water reef coral Goniastrea aspera Verill 1865 has previously been reported to demonstrate differences in within-colony susceptibility to bleaching at elevated sea temperatures; parts of the colony which are exposed to the highest solar radiation are more thermotolerant than areas which are less exposed. In this paper, we show that at elevated experimental sea temperature the Œhigh light¹ surfaces lose fewer symbiotic algae, have lower levels of oxidative stress, higher levels of host antioxidant-enzyme copper zinc superoxidase dismutase (CuZnSOD), and host heat-shock proteins 60 and 70, compared to the less exposed surfaces. In addition, Œhigh light¹ surfaces show less chronic photoinhibition and greater Photosystem II (PS II) recovery potential when exposed to high irradiance at ambient sea temperature. In contrast, no differences were noted in algal defences (e.g. antioxidant enzymes and stress protein production, and xanthophyll cycling) either at elevated or ambient temperatures. These results are noteworthy because they suggest that corals which acclimatise to high irradiance can, as a result, develop increased thermotolerance which may prevent bleaching at high sea temperatures. Importantly, they also demonstrate the significance of the host tissues in maintaining the intact symbiosis of G. aspera under thermal stress. KEY WORDS: Corals · Thermotolerance · Acclimatisation · Irradiance stress Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 242. Online publication date: October 25, 2002 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2002 Inter-Research.