Water-Cooled Great Barrier Reef Also Gets A Dusting, Playfuls.com, 03/12/07
There was good news and bad news Monday for the 2 million tourists who visit Australia's Great Barrier Reef each year.
While an unusually heavy monsoon season in the north-east corner of the continent has served to cool down corals that cover an area the size of Germany, the extra sediment spewed out of river estuaries is creating a hazy cloud over the reef that cuts down sunlight and holds back the process of photosynthesis that keeps organisms alive.
One of the wettest wet seasons on record has served to reduce temperatures. But marine scientists said the reef was still at long-term risk from climate change because coral doesn't have a mechanism to cope with the higher temperatures that rob water of its nutrients.
Ray Berkelmans, a coral bleaching expert with the Australian Institute of Marine Science, said all the coral could be gone by 2025 if global warming keeps pushing up the water temperature.
"Background temperatures have reached the level where every summer we are getting to dangerous conditions," Berkelmans said. "It will be a gradual decline - patch by patch and species group by species group, from one area after another."
The bad news was that torrential rain had flushed out sediment and deposited it over a greater area of the reef than experts had expected.
The government's Commonwealth Scientific and Industrial Research Organization (CSIRO) said satellite images showed plumes of sediment extending over the reef as a consequence of very heavy rainfall in far north Queensland.
Initially experts had thought that the sediment settled quickly and that the dusting didn't extend far into the reef. The images produced by United States authorities showed that not to be the case.
Prime Minister John Howard's government is a straggler in global attempts to slow climate change. Australia, along with the United States, has refused to ratify the Kyoto Protocol that sets signatories legally binding targets for the reduction of the greenhouse gases that cause global warming.
Along with Washington, Canberra argues that cutting back on emissions would slow its economy. On a per capita basis, Australia is the world's biggest generator of greenhouse gases, while the US is the biggest polluter overall.
© 2007 DPA