More than a quarter of the world's coral reefs have been destroyed by pollution and global warming, experts said today, warning that unless urgent measures are taken, most of the remaining reefs could be dead in 20 years.
In some of the worst hit areas, such as the Maldives and
Seychelles islands in the Indian Ocean, up to 90 percent of coral
reefs have been killed over the past two years due to rises in water temperature.
Coral reefs play a crucial role as an anchor for most marine
ecosystems, and their loss would place thousands of species of fish
and other marine life at risk of extinction.
Addressing 1,500 delegates from 52 countries at the 9th
International Coral Reef Symposium on the island of Bali,
researchers warned that governments must urgently reverse global
warming trends, cut pollution and crack down on overfishing.
"You have to go and look at the coral reefs now, as we are
losing them," said Clive Wilkinson, a leading Australian
Wilkinson said that in some areas fishermen use dynamite or
cyanide to catch fish, blowing the reefs apart or poisoning them.
In other areas, governments pump untreated sewage and other waste
directly into oceans.
But the most serious and immediate threat to the world's reefs
is global warming, which causes a damaging condition known as coral
bleaching. This occurs when higher water temperatures heat up the
coral, causing them to expel the microscopic plants that give them
their vibrant color. If the coral is not cooled, it dies.
Oceanographers say the El Niño weather pattern two years ago,
which led water temperatures to rise by up to six degrees, did
enormous damage to the coral reefs, some of which had been alive
for up to 2.5 million years.
Australian scientist Ove Hoegh-Guldberg said 26 percent of coral
reefs around the world have already been destroyed and in another
20 years, water temperatures are likely to rise to the point where
corals will be sitting in a "hot soup" in which they are unable
Wilkinson said the loss of the reefs would not only be a major
blow to the environment, but would also threaten the livelihood of
a half billion people around the world who rely on them for food
The reefs bring in an estimated $400 billion a year in fishing
and tourism revenues.