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Automatic weather stations such as this one at Davies Reef are used to collect weather and water temperature data. This data is used to generate near real-time warnings of coral bleaching. (Photo courtesy of the Australian Institute of Marine Science.)

network of weather stations and an innovative computer expert system is now in place to monitor and alert us to environmental conditions that may be stressful to corals, much as smoke alarms provide early warning of fire. This is one of the outcomes of a research collaboration between the Great Barrier Reef Marine Park Authority (GBRMPA), the Australian Institute of Marine Science (AIMS) and the United States based National Ocean and Atmospheric Administration (NOAA). As part of this collaboration, GBRMPA is installing two new automatic weather stations on the inshore Great Barrier Reef to compliment four existing weather stations on the offshore Great Barrier Reef run by AIMS. These weather stations provide near real-time feedback on weather and sea temperatures out on the reef. Data are sent every evening to NOAA’s Atlantic Oceanographic and Meteorological Laboratory in Miami, Florida where the data are processed by a computer expert system. Automated warnings are sent out when given triggers, representing theorised stressful conditions, are exceeded. Such warnings will assist:

1. Science—in the timely monitoring and improvement of our understanding of coral bleaching;
2. Public relations—in keeping commercial operators on the Great Barrier Reef, politicians and the general public informed; and
3. Coral reef managers—in amelioration of local-scale human impacts which might exacerbate coral bleaching.

Since the global coral bleaching event of 1998, which caused widespread coral morality particularly in the Indian Ocean, scientists are keenly aware of environmental conditions which are stressful to corals. Those conditions tend to occur when temperatures are high, winds are calm and solar radiation is high. An early warning system based on these parameters successfully predicted the onset of coral bleaching in the Florida Keys in August 1998. This encouraging achievement paved the way for the development of a similar system for the Great Barrier Reef using local weather stations and exceedence thresholds.

Preliminary thresholds were developed and implemented in an early warning system for four weather stations on the Great Barrier Reef for the 1999–2000 summer. Although still in a pilot phase, the system has already had success in alerting AIMS and GBRMPA to minor coral bleaching at Myrmidon Reef at the end of January 2000. The warm season started with unusually cool water temperatures, overcast skies and generally strong winds in November, December and most of January. However, the last two weeks of January saw a complete turnaround in this weather pattern with clear skies and light northerly breezes resulting in a drastic warming of sea temperatures. Alerts of possible bleaching conditions were received for Myrmidon Reef near Townsville and Agincourt Reef near Port Douglas between 29 and 31 January. AIMS scientist Emre Turak visited Myrmidon Reef on 14 February and saw clear evidence of mild bleaching on the reef flat, despite temperatures having dropped from a high of 29.7°C in late January to around 28°C. Describing the bleaching he wrote:

‘Bleaching was only partial and exclusive to a number of species. All Acropora gemmifera appeared to be affected with various degrees of paling or fluorescing. Acropora digitifera was another species which appeared affected while other species in the humilis group (A. humilis and monticulosa) and other Acropora spp. were not touched.’

Although this observation points to localised and mild bleaching, the early warning system at Myrmidon Reef clearly shows potential. Having this advance notice of possible bleaching allowed for a coordinated documentation of bleaching through incidental observations by scientists from a wide range of organisations. Luckily, the warm water temperatures of late January abated in February, and a more widespread bleaching event was avoided.

The bleaching alert for Agincourt Reef turned out to be a false alarm. Staff from Reef Biosearch who operate reef interpretation services at Quicksilver’s pontoons at Agincourt #3 and 2d reported no unusual paling of Acropora gemmifera or other corals species at their sites. Alarm triggers were initially set at the same levels for both Agincourt and Myrmidon Reefs. As environmental conditions were very similar on both reefs during this period, the false alarm indicates that coral communities on these two reefs, separated by approximately 330 kilometres, may have different tolerance levels to bleaching. This is encouraging news as it implies that some coral populations may be better adapted to thermal stress than others and may therefore be more resilient to potential future climate warming. Expert system rules are currently being re-programmed for Agincourt Reef to adjust alarm triggers as a result of this feedback.

New weather stations on the inshore Great Barrier Reef in Cleveland Bay, near Townsville and Keppel Bay, near Rockhampton will complement offshore weather stations at Agincourt Reef, Myrmidon Reef, Davies Reef and Hardy Reef to provide a better representation of the Great Barrier Reef. With the weather station network in place and close collaborative links forged with NOAA, further possibilities are opened up using interpreted near real-time weather data. For example, NOAA has already developed an expert system to predict the sea state and wave height at Myrmidon Reef. In time, similar expert systems may provide predictions of underwater visibility, coral spawning, fish migration, algal blooms, etc. Data from the Great Barrier Reef automatic weather stations can be seen at http://www.aims.gov.au/pages/weather%20index.html and information on the research collaborative with NOAA is available at http://www.coral.noaa.gov/corvil/.

	Price ($)
	Ayling, A.M. and Ayling, A.L. 1999, Medium-term Changes in Coral Populations of Fringing Reefs at Cape Tribulation, Research Publication No. 59, Great Barrier Reef Marine Park Authority, Townsville, 46 pp.	n/c
	Mapstone, B.D., Ayling, A.M. and Choat, J.H. 1999, A Visual Survey of Demersal Biota in the Cairns Section of the Great Barrier Reef Marine Park, Research Publication No. 60, Great Barrier Reef Marine Park Authority, Townsville, 42 pp.	14.85*
	Ormsby, J. and Shafer, S. 2000, Visitor Experiences, Values and Images of Whitehaven Bay: An Assessment of Perceived Conditions, Research Publication No. 62, Great Barrier Reef Marine Park Authority, Townsville, 83 pp.	21.40*
	KPMG Consulting 2000, Economic and Financial Values of the Great Barrier Reef Marine Park, Research Publication No. 63, Great Barrier Reef Marine Park Authority, Townsville, 42 pp.	12.60*
	* Price includes postage within Australia by surface mail and the Goods & Services Tax (GST). Copies of these reports are available from Reef In Store (telephone +61 7 4750 0875).