International marine scientists say that a huge coral death which has struck Southeast Asian and Indian Ocean reefs over recent months has highlighted the urgency of controlling global carbon emissions.
Many reefs are dead or dying across the Indian Ocean and into the Coral Triangle following a bleaching event that extends from the Seychelles in the west to Sulawesi and the Philippines in the east and include reefs in Sri Lanka, Burma, Thailand, Malaysia, Singapore, and many sites in western and eastern Indonesia.
“It is certainly the worst coral die-off we have seen since 1998. It may prove to be the worst such event known to science,” says Dr Andrew Baird of the ARC Centre of Excellence for Coral Reef Studies and James Cook Universities. “So far around 80 percent of Acropora colonies and 50 per cent of colonies from other species have died since the outbreak began in May this year.”
This means coral cover in the region could drop from an average of 50% to around 10%, and the spatial scale of the event could mean it will take years to recover, striking at local fishing and regional tourism industries, he says.
The bleaching event has also hit the richest marine biodiversity zone on the planet, the ‘Amazon Rainforest’ of the seas, known as the Coral Triangle (CT), which is bounded by Indonesia, Malaysia and the Philippines.
Dive operators have recorded water temperatures of 34 C, over 4 degrees higher that than the long term average. Professor Ove Hoegh-Guldberg from the ARC and the director of the Global Change Institute at the University of Queensland talking on The World Today said:
If you look at the satellite sea surface temperature measurements, they’re showing that seas are about one to three degrees warmer than the long-term averages for the region.
And that, if oceans remain at it for a month or two months, is enough to cause reefs to experience severe coral mortality.
It seems that the Indian Dipole event, which involves pooling of warm water in the eastern Indian Ocean, may have been involved and was accentuated by climate change. I’ve heard that the Indian Dipole is one of the factors giving us unusually wet weather in parts of Australia in recent months.
What this means for the Great Barrier Reef, we will have to wait and see, but those of us who are feeling cool in Brisbane for this time of the year would be unwise to call the end of global warming. Climate Progress links to a NASA GISS commentary on the northern hemisphere summer temperatures.
Summer in 2010 figures as the fourth warmest on record. With the late breaking La Nina, calendar 2010 looks less likely to be a record, but GISS have lately been looking at running 12-month periods. Here they found that the 12 months to mid-2010 broke the record. In Russia the summer heat has been estimated as a once in every 15,000 years event.
For the coral reefs it’s a case of if the bleaching doesn’t get you the ocean acidity will.