Coral Bleaching Work Group Major Research Themes

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Ultimate guide to managing coral disease
8 July 2008: The definitive management guide - handbook plus id cards for Caribbean and Indo-Pacific regions - to identifying, assessing and managing coral reef diseases was launched at the 11th International Coral Reef Symposium (ICRS) and can be ordered online now.
[Read media release] [Read summaries] [Order online] [Visit CRTR at ICRS booth 418]

Top award for CRTR researcher
21 May 2008: CRTR Program researcher, Professor Ove Hoegh-Guldberg, has been awarded the Queensland Government’s top science award. Chair of the CRTR Bleaching Working Group, and also of its Australasian Centre of Excellence, Professor Hoegh-Guldberg was one of the world's first scientists to show how projected changes in global climate threaten coral reefs including Australia's Great Barrier Reef......
[Read UQ News]

Indian Ocean coral shows partial recovery
15 May 2008: An unusual spike in sea temperatures a decade ago killed coral throughout the Indian Ocean, dropping the average healthy, hard coral cover to 15 percent of reefs from 40 percent before. CRTR researcher, Dr Tim McClanahan, said hard coral cover had recovered to 30 percent by 2005, although the data masked big variations.....
[Read Reuters Africa article]

Strange days on planet earth
5 May 2008: The award winning National Geographic program Strange Days on Planet Earth recently premiered Episode 6 (Dirty Secrets). This features the CRTR Program’s Roberto Iglesias-Prieto and his colleagues in the Caribbean who are “studying how CO2, one of our largest industrial waste products, is impacting coral reefs”.
[Read article]

Corals on the brink of .....
24 April 2008: Predicted mass spawning at Palau (Philippines) was the subject of a feature on BBC News on 20 April. Much of the article focused on the reef restoration work of CRTR scientists Dr Andrew Heyward (“one of the first biologists to describe the phenomenon of coral mass spawning in the 1980s”) and Dr James Guest, along with Dr Maria Vanessa Baria from the University of the Philippines.
[Read article]

Coral-Symbiont Responses to Thermal Stress

Reef-building coral and their symbionts are critical to coral reefs as the ‘frame builders’, providing the habitat for tens of thousands of organisms. They are also among the organisms most affected by climate change at this point. While bleaching events have profound effects on coral reefs, we know little about the mechanisms behind bleaching, the differences in susceptibility of different corals and symbionts and how physiological stress translates into ecological changes at the reef level.

The Bleaching Working Group is pursuing projects aimed at resolving the molecular mechanism of stress, and determining what characteristics of corals and their symbionts drive their different tolerances to stress. The group is compiling a library of symbiont genotypes for each of the four CRTR regions and is exploring how different these symbionts are in terms of their physiology inside and outside the coral host.

The Bleaching Working Group is also looking at coral ‘associates’, the wide variety of organisms that live in close association with corals. These associates are thought to play a prominent role in coral health and the group is exploring their role in bleaching and disease in conjunction with other groups within the CRTR.

Organismal Mechanisms to Ecological Outcomes

Changes to the physiological and cellular function of reef-building corals and their dinoflagellate symbionts invariably result in changes to their life-history parameters. These in turn result in changes to the population dynamics of reef-building coral. This research area aims to better understand changes to reproduction, mortality and other aspects of coral populations to establish better projections for the future.

The Bleaching Working Group has set established permanent study sites in Zanzibar, Puerto Morelos and Heron Island. At these sites, researchers are exploring the population dynamics under natural and perturbed conditions, as well as spatial patterns in population size frequency distributions and temporal changes of the populations in and out of bleaching events.

Work within this research area also aims to resolve the potential impacts of changes in coral health on the many other species that are dependent on coral reefs for food and shelter. The Bleaching Working Group is summarizing the existing data on the impact and disturbances on fish and other species during bleaching events where coral was lost.

Biomarkers of Stress

One of the problems often facing reef managers and policy makers is that they are confronted with reefs in which damage has occurred however the reasons for the damage are less than clear. In this respect, determining whether changes are due to climate change or declining water quality can have implications on the direction a reef manager may take.

The Bleaching Working Group is working on distinguishing different stress responses with corals and their symbionts. Research will use microarray technology to generate a series of markers at molecular and physiological levels. The ultimate goal will be to have tools so reef managers can distinguish different stresses on coral.

The Bleaching Working Group is also investigating the use of a colour card for quantifying the detection of changes in coral colour. This tool will allow users to assess coral bleaching within at least 10 levels, far greater than the existing three levels used by previous studies.

Projections of Change and Socio-Economic Impact

Ultimately, managers need to know how coral reefs will change as the world’s oceans warm and acidify. This will ensure effective management and policy responses in the future.

The insights of the CRTR Program Bleaching Working Group into how reef-building corals and reefs respond to stress will build the foundation for understanding the rate, detail and direction of change on coral reefs as the climate changes.

Towards the end of the first phase of the Coral Reef Targeted Research Program, the Bleaching Working Group will broker a series of meetings to assemble details of potential climate impacts in the coming decades. This information will be incorporated into strategies to assist in adaptive responses by coral reef management.

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