1 February 2006
The bleaching observed by marine researchers and tourist operators on reefs in the Capricorn region confirmed the AIMS/GBRMPA weather station data that show sea surface temperatures (SSTs) in this area are well above critical levels for normal coral function. SSTs in the Keppels have been hovering 2 degrees C above the average since early December, and this sustained warm period caused temperature-sensitive corals to reach bleaching thresholds as early as Christmas.
AIMS scientist and a world authority on coral bleaching, Dr Ray Berkelmans said "This is up to a month earlier than we've seen in previous bleaching events in 1998 and 2002. Since there is still a long way to go this summer, these conditions do not bode well for reefs in the Keppels".
Map showing the Queensland coast on the Coral Sea. Red circle indicates the study area of the story.
But AIMS coral bleaching researchers remain optimistic, hoping for a repeat of the recovery witnessed on Keppel reefs following major bleaching episodes in 1998 and 2002.
AIMS scientists were at the forefront in documenting the wrath of those dramatic summer heatwaves that bleached reefs worldwide. Dr Berkelmans, said the Keppels suffered near 100% bleaching during those events but this area also recovered 3-6 months later, revealing a remarkable resilience not seen in many other places on the Great Barrier Reef.
Research in the Keppel Islands is showing this area to be pretty special. "We have found that corals have the ability to change the type of algae they associate with and that this alters their thermal tolerance. Corals in the Keppels also seem to grow faster than their northern counterparts and store more fats. We believe this may be at least part of the reason why the Keppels are able to bounce back from a heat wave that had dire consequences for other regions," Dr Berkelmans said.
AIMS Scientists are hopeful of a similar recovery following this bout of bleaching and will audit the situation in three weeks time as well as conduct more experiments.
AIMS works closely with GBRMPA and the University of Queensland in monitoring and researching the effects of coral bleaching.
A typical example of bleached coral on the GBR. Image: AIMS
For more information on weather station and satellite SSTs go to: www.reeffutures.org/topics/bleach/LongTermTemperature.cfm and www.aims.gov.au/pages/remote-sensing.html Click on "Sea surface temperature web atlas" at the bottom of the page Choose a date (yesterday's if before 5pm) Click the "go" button.
Dr Ray Berkelmans, AIMS Research Scientist
Telephone: 07 4753 4268
Wendy Ellery, AIMS Communication and Media Liaison
Telephone: 07 4753 4409
Fax: 07 4771 6138
Mobile: 0418 729 265