Indo-Pacific coral reefs dying at a faster rate than previously thought

Corals in the Indo-Pacific region are dying faster than previously envisaged, a new study by researchers from the University of North Carolina has revealed.

Washington, Aug 8 : Corals in the Indo-Pacific region are dying faster than previously envisaged, a new study by researchers from the University of North Carolina has revealed.

Corals were disappearing at an astonishing rate of nearly 600 square miles in the central and western Pacific Ocean, twice the rate of rainforest loss. Historically, coral cover, a measure of reef health, hovered around 50 percent. But, today, only about two percent of reefs in the Indo-Pacific have coral cover close to the historical baseline, the study said.

Lead author, Associate Professor of marine biology, John Bruno said the reefs were disappearing at a rate of one percent per year, a decline that began decades earlier than expected.

"We have already lost half of the world's reef-building corals," said Prof. Bruno.

As part of the study, Prof. Bruno and graduate student Elizabeth Selig compiled and analyzed a database of 6,000 quantitative surveys performed between 1968 and 2004 of more than 2,600 Indo-Pacific coral reefs.

The surveys tallied coral cover, a measure of the ocean floor area covered by living corals.

Scientists rely on coral cover as a key indicator of reef habitat quality and quantity, similar to measuring an area covered by tree canopy as a gauge of tropical forest loss.

Results showed that the coral cover had declined from 40 percent in the early 1980s to approximately 20 percent by 2003. But more surprising was the fact that coral cover loss in habitats maintained by conservationists was just as extensive as in unprotected reefs.

Prof. Bruno believes the consistent pattern of decline across the entire Indo-Pacific is a likely global phenomenon, possibly due to large-scale stressors such as climate change.

"Indo-Pacific reefs have played an important economic and cultural role in the region for hundreds of years and their continued decline could mean the loss of millions of dollars in fisheries and tourism. Its like when everything in the forest is gone except for little twigs, a few lone trees," said Selig.

The results appear in the Aug 8 online issue of the journal PLoS One.

ANI