Scientists are concerned that bleaching may reach the same levels or exceed those recorded in 2005, the worst coral bleaching and disease year in Caribbean history. There is also some potential for high stress in the central Gulf of Mexico and a region stretching from the Lesser Antilles, including the US Virgin Islands, across to Puerto Rico, and across to the southern coast of Hispaniola and the Caribbean coast of Nicaragua.

Other areas of concern for coral bleaching this year are the central Pacific region including the equatorial Line Islands and Kiribati.  Some thermal stress may also develop between the Northern Mariana Islands and Japan.

An important caveat is that the model used for this outlook is not yet calling for El Niño development, whereas NOAA’s operational Climate Forecast System is now calling for development of an El Niño during 2009-10. If El Niño continues to strengthen, this could increase the bleaching risk in the central to eastern Pacific and Caribbean.

Just like any climate forecast, local conditions and weather events can influence actual temperatures. However, we are quite concerned that high temperatures may threaten the health of coral reefs in the Caribbean this year.

The Thermal Stress Outlook is based on sea surface temperature (SST) forecasts generated by the Linear Inverse Model (LIM) from the NOAA Earth System Research Laboratory. This system is the first to use sea surface temperature forecast models to provide seasonal outlooks of bleaching around the world.

In the Pacific, the area of concern includes the equatorial Line Islands and Kiribati. This area is especially subject to stress if El Niño development continues.  There is a potential for some thermal stress to develop between the Northern Mariana Islands and Japan. There is also some indication of thermal stress along the Pacific coast of Mexico. However, the model is only generating small areas in the Pacific with a potential for abnormally high temperatures. Care should be taken that areas of warming in open areas of the Pacific are likely to move from the locations seen in the current forecast models. This region is also subject to intensification during El Niño conditions.

The NOAA Coral Reef Watch forecast comes on the heels of NOAA’s National Climatic Data Center reporting in June that the world’s ocean surface temperature was the warmest on record, breaking the previous high mark set in 2005, the last year of record-setting global coral bleaching incidents. Updates can be found here. Divers who see bleaching can report it at ReefBase.

In its inaugural year the forecast system did well in predicting the general patterns of mild Caribbean stress in 2008 and high thermal stress in the western Pacific in 2008-9, especially earlier in the season. The guidance issued in early December provided valuable guidance on the potential for bleaching 2-4 months in advance. The general pattern of warming in the outlook corresponded well with large-scale patterns of actual thermal stress. However, strong monsoonal activity along northeastern Australia cooled waters on the Great Barrier Reef (GBR) reducing thermal stress there. This was a fortunate difference between the forecast and actual conditions that protected these valuable reef resources.

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comes another ‘bona fide’ report ( “CO2, Global Warming and Coral Reefs: Prospects for the Future“)  aimed at debunking the widely respected view among the scientific community that increases in temperature and atmospheric CO2 are detrimental to the future of coral reefs. In fact this report by the Science and Public Policy Institute of Washington, argues that these ‘twin evils’ actually have positive effects on coral reefs worldwide promoting growth and calcification (link). While this non peer-reviewed report claims to be based on sound science, with close to 200 references (many of which are from leading experts in the coral reefs), it is the misinterpretation of these research articles that makes this report a sure standout among climate skeptic pieces to date.

Reading through this report may make you want to pull out a red pen and scribble all over what seems reads like a misinformed undergraduate essay. The key point claiming that there is no simple linkage between high temperatures and coral bleaching may be a far reach from the evidence that shows a hot prolonged summer with temperatures above the monthly maxima will guarantee coral bleaching.

Throughout the report, the authors use ‘snippets’ from papers to attempt to justify their hypotheses. For example, discussing  the effects of thermal acclimation in reducing bleaching severity and mechanisms for adaptation (such as Middlebrook et al [2008]) is out of context, and somewhat akin to saying you can milk a cake from a cow, without consideration of the steps in between.

The report states that ‘real-world’ observations paired with the sound science reviewed in the report ‘refute the claims of climate alarmists’ through the following findings:

“A particularly ingenious way by which almost any adaptive response to any type of environmental stress may be enhanced in the face of the occurrence of that stress would be to replace the zooxanthellae expelled by the coral host during a stress-induced bleaching episode by one or more varieties of zooxanthellae that are more tolerant of the stress that caused the bleaching”

“Rising sea levels may actually have a positive effect on reefs, permitting increased coral growth in areas that have already reached the upward limit imposed by current sea level”.

“Theoretical predictions indicate that coral calcification rates should decline as a result of increasing atmospheric CO2 concentrations by as much as 40% by 2100. However, real-world observations indicate that elevated CO2 and elevated temperatures are having just the opposite effect.”

While there is hope that corals will adapt to a changing environment, the predicted rate of temperature and atmospheric CO2 change is unprecedented, higher than anything seen in the last 720,000 years during which coral reef ecosystems evolved.

These predictions, paired with the knowledge of the sensitiveness of coral reef ecosystems to change, encourage scientists to be prudent when advocating the resilience of coral reefs. Given the funding history of the institute, and their pseudoscientific interpretations of previous publications, a report like this isn’t exactly surprising. Whilst a report like this may be fodder for the likes of climate skeptics around the world, it takes on a far more serious note when it is aimed at ‘educating’ policy makers in government, whom without proper consultations with established scientists, just might take this report seriously. The irony is, this is a frightening possibility.

The NOAA Coral Reef Watch Bleaching Thermal Stress Outlook indicates that the greatest chance of bleaching during the upcoming austral summer will be in the region bounded by Papua New Guinea, the Solomon Islands, and the northern Great Barrier Reef (GBR). The figure above shows the most recent global 17-week Coral Bleaching Thermal Stress Outlook from the 09 December 2008 model run.

Actual conditions for December show temperatures around the central GBR 0.75-1.0 degrees Celsius above the MMM +1 (mean monthly maxima), and above 1 degrees Celcius to the Northern GBR and waters SE of PNG (Link). Recent SST changes have also been mapped by the Australian Bureau for Meteorology and confirm gradual warming on the GBR despite sub surface cooling in the central to eastern pacific.

Current SST tracking on Heron island on the southern GBR shows temperatures following a similar profile to that of the 2001/2002 bleaching event. The increase in SST over the next month will be critical in determining the risk of bleaching across southern GBR.

The majority of dynamic computer models are predicting neutral climate conditions to continue through the southern summer, however, some models are predicting a return to La Niña conditions which may drive monsoon, storm like conditions and generate some cooling in Queensland (Link). More updates as they come.

Using an experimental algorithm developed from satellite monitoring of sea surface temperatures, the National Oceanographic and Atmospheric Administration (NOAA) are able to predict (often with some accuracy) the coral bleaching outlook for the upcoming season (for more information on the model itself, see this link).The forecast for the Austral summer (Nov ’08 – Feb ’09) is intensifying, with potential ‘severe bleaching’ predicted in the Northern sectors of the GBR – so much so that the Great Barrier Reef Marine Park Authority is concerned about the rising sea temperatures.

The area most likely to suffer thermal stress with the potential for severe bleaching during the next 15 weeks is a region spanning Papua New Guinea, the Solomon Islands, and the Far Northern section of the GBR. Less severe thermal stress is a expected in a broader region including all of the Cairns section of the GBR. To the west, the model currently predicts a threat of moderate levels of thermal stress from southern Borneo across through Timor-Leste to southern Papua New Guinea and Torres Strait. This level of potential stress then picks up in the central GBR and east extending across Vanuatu and New Caledonia to the east-southeast of Fiji. Some mild stress may be seen around Madagascar. The greatest warming is expected to begin from late January through February.

It seems that the northern GBR is likely to be affected with the occurence of localised bleaching, but the impact across broader scales (i.e southern GBR) looks less severe. Given that the Bureau of Meterology are predicting a cyclone season “on the upper side of normal“, the impacts of cyclones passing through the coral sea could potentially dissapate the thermal stress build up that triggers coral bleaching (read more). We will keep posting updates on the 2008/2009 season as the bleaching outlook changes.