The Great Barrier Reef has recovered from severe bleaching and is now one of the world’s healthiest coral reefs, the Australian Institute of Marine Science said in a report issued yesterday.
Coral on almost 60% of the reef was dying because the water was becoming too warm for it, but was now recovering. Now only about 6% of the vast reef off the north-east coast of Australia is affected.
When the algae that populate and build the corals die the reef turns a ghostly white. This happens when the water gets too warm or the algae are affected by overfishing, pollution and sedimentary runoffs from coastal development.
The 2002 Report on the Status of the World’s Coral Reefs paints a mixed picture for the future of reefs elsewhere, although it is clear that if they are properly managed they can recover completely.
It was feared after the El Nino event of 1997/8, which raised the water temperature in the Pacific to a record level, that the corals would never recover, but the fear was misplaced.
”Reefs, if they are left alone and not stressed, they will recover quite rapidly,” said Dr Clive Wilkinson, who heads the Global Coral Reef Monitoring Network.
The Great Barrier Reef, 1 200 miles long, is the biggest complex of coral reefs and islands in the world, listed as a World Heritage Site, and one of Australia’s most popular tourist attractions. It comprises more than 2 600 individual reefs and 300 islands.
The report praised the federal great barrier marine park authority for preserving the reef by ensuring the quality of its water, protecting fish stocks and setting up marine sanctuaries.
Wilkinson said many coral reefs were still on the cusp of surviving or dying from coral bleaching, and their future depended on the political will of governments.
In south-east Asia, which has the biggest area of reefs, 88% are reported to be at medium to high risk because of human impacts.
The most serious threats are destructive overfishing, including the use of explosives, coastal development, increased sedimentation, and pollution.
Development is taking priority over environmental conservation, but some communities are successfully protecting reefs, the report says.
It says that £62m a year is spent on conserving them, but their direct value in food and building products, tourism and biodivesity alone is £250bn. – Guardian Unlimited Â