Indian Ocean could lose its coral islands

Indian Ocean could lose its coral islands

The Indian Ocean could lose most of its coral islands in the
next 50 years if sea temperatures continue to rise and reefs
badly damaged by global warming do not recover, a marine
scientist has said.

Global warming triggered the death of between 50 and 98
percent of coral reefs in a region stretching from northern
Mozambique to Eritrea to Indonesia in 1998 and although there has
been some recovery, scientists remain concerned.

"We have reason to believe that if climate changes continue
due to the carbon dioxide that is being pumped into the
atmosphere, the temperatures at ground level and in the oceans
will go up," Dr Carl Lundin, head of the marine program of the
Swiss-based World Conservation Union (IUCN), said.

"So virtually all the coralline islands have a decent chance
of disappearing in 50 years," Lundin told Reuters in Victoria,
the capital of the Seychelles, recently.

Coral reefs are among the most diverse and productive
communities on earth. Found in warm, clear, shallow waters of
tropical oceans worldwide, reefs have functions ranging from
providing food and shelter to fish and invertebrates to
protecting the shore from erosion.

Many coral reef organisms can only tolerate a narrow range of
environmental conditions and are very sensitive to damage from
environmental changes such as rising temperatures which can cause
bleaching and eventual death.

Lundin said sustained warming up of ocean currents which
followed the El Nino effect in 1998 resulted in bleaching and
widespread damage to corals in the Indian Ocean.

"So a very large region has been affected and an awful lot of
damage has been caused by the temperature increases which varied
from one to two to generally up to five degrees Celsius."
According to Lundin, the Seychelles' coralline islands of
Amirantes, Aldabra, Bird island and Denis island which support
unique ecosystems are seriously threatened.

"These islands are made of fossil reefs that have been raised
out of the water but as erosion continues, they are likely to be
gnawed away," said Lundin.

Lundin said there was some coral recovery with islands which
lost up to 100 percent of their coral cover in 1998 having
regained between two and 20 percent of their cover.

He attributed the gradual recovery of corals in Seychelles to
time and the lack of negative development. -- Reuters