Coral reefs “will die in decades” unless protected
By Vanessa Houlder in London
FT.com - Financial Times
15th August 2003
Life on the world's coral reefs will not survive for more than a few decades without immediate protection from human exploitation, according to a report in today's Science journal.
Coral reefs and their ecosystems are in jeopardy because of overfishing and pollution, compounded more recently by disease and bleaching. Bleaching occurs when overheated corals expel the algae that give reefs their vibrant colours.
Australia's Great Barrier Reef, the best-protected reef in the world, is nearly a third of the way toward extinction. Where the process is most advanced, such as Jamaica, the corals are either dead or dying, there are few fish and the reef is coated with algae.
Most reef ecosystems were substantially degraded before 1900. "Recent widespread and catastrophic episodes of coral bleaching and disease have distracted attention from the chronic and severe historical decline of reef ecosystems," according to the researchers from US and Australia.
The downward spiral began when people began killing the large fish, turtles and seals frequenting the reefs, a process that started thousands of years ago. The reduced number of herbivorous fish and added nutrients from pollution causes seaweed to become dominant.
The increased frequency and magnitude of coral bleaching over the last 30 years is incontrovertibly linked to climate change, according to another paper by an international team in Science. In 1998, 16 per cent of the world's corals were killed as a result of bleaching.
But some species show greater tolerance to climate change than others, suggesting that "at a global scale, reefs will undergo major changes in response to climate change rather than disappear entirely".