Beltran, Victor H., Dunlap, Walter C., and Long, Paul F. (2012) Comparison of the photosynthetic bleaching response of four coral species common to the central GBR. In: Proceedings of the 12th International Coral Reef Symposium. 9A_3. pp. 1-6. From: 12th International Coral Reef Symposium, 9-13 July 2012, Cairns, QLD, Australia.

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Abstract

The photosynthetic bleaching response of Acropora microphthalma, Acropora formosa, Stylophora pistillata and Pocillopora damicornis were compared under empirical conditions of environmental stress. Coral specimens were collected at Davies Reef located in the central region of the GBR from a depth of 10-15m and were exposed to natural and shaded light under temperature-controlled conditions for 48 h at a depth of 40 cm held within a shipboard, light-exposed tank. After 2 days of stress (high light/low temperature, high light/high temperature, and low light/high temperature), the acroporids were severely bleached whereas the Stylophora and Pocillopora specimens had retained some pigmentation. Light-adapted PSII Yield values declined to 0.1-0.2 units at midday in all coral species but had increased by partial recovery during the afternoon periods of exposure. From these 2-day experiments, the rate of PSII Yield recovery (Yr), calculated as the increment of light-adapted PSII Yield that had recovered from midday to dusk, were compared. Results of Yr determinations showed that A. formosa is a thermally sensitive species having reduced Yr values under both light conditions. A. microphthalma and S. pistillata were more thermally tolerant but light sensitive with greater Yr values under low light than under high light exposure. Pocillopora was least sensitive to bleaching and showed attributes of light and thermal tolerance with up to six times greater Yr values than the other coral specimens examined under identical conditions. The bleaching response of these corals under different stress conditions will be discussed in context with the photosynthetic response of their symbionts measured in hospite.

Item ID:	22383
Item Type:	Conference Item (Research - E1)
ISBN:	978-0-9808572-5-2
Keywords:	PSII recovery rate, Symbiodinium, coral bleaching
Related URLs:	Organisation
Additional Information:	© Copyright belongs to the authors.
Date Deposited:	10 Sep 2012 23:44
FoR Codes:	06 BIOLOGICAL SCIENCES > 0602 Ecology > 060205 Marine and Estuarine Ecology (incl Marine Ichthyology) @ 100%
SEO Codes:	96 ENVIRONMENT > 9608 Flora, Fauna and Biodiversity > 960808 Marine Flora, Fauna and Biodiversity @ 100%
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