SYDNEY, Australia — A new report warns that rising ocean temperatures will kill most of the coral on the Great Barrier Reef by 2050, an official said Sunday.

The report by Queensland University's Center for Marine Studies said the Pacific Ocean is getting too warm too fast for the survival of the world's largest chain of living coral.

The Worldwide Fund for Nature and Queensland state's main tourism body commissioned the report, which was partly funded by the government.

The reef, which stretches 1,200 miles along the Queensland coast in northeastern Australia, is one of the country's biggest tourist attractions, pumping billions of dollars into the state's economy.

"Coral cover will decrease to less than 5 percent on most reefs by the middle of the century, under even the most favorable assumptions," said the study, excerpts of which were published in the weekend edition of The Sydney Morning Herald.

"There is little to no evidence that corals can adapt fast enough to match even the lower projected temperature rise," it said.

Studies have found that a rise in water temperature of less than 1.8 degrees Fahrenheit correlates directly with coral deaths and bleaching -- when coral loses its vibrant colors. Analysts have predicted that water temperature will rise between 3.6 and 10.8 degrees F this century.

The conservative government of Prime Minister John Howard has made attempts to limit damage to the reef, but Australia -- along with the United States and Russia -- has refused to sign the Kyoto treaty on global warming.

Last year the government increased the size of high-protection zones on the reef from 4.5 percent to 33.3 percent of its total area, or from 6,200 square miles to 44,000 square miles. In these areas, fishing is banned and tourism is the only industry allowed.

Authorities say fishing and the runoff of sediments after heavy rains also hurt the reef and make it more susceptible to bleaching.

A spokesman for the Environment Ministry said Sunday that the report was "a good contribution to debate about the reef from a constructive organization."

To come into force, the Kyoto Protocol must be ratified by no fewer than 55 countries, accounting for at least 55 percent of global emissions in 1990. That minimum can now only be reached with Russia's ratification because the United States and several other nations have rejected the treaty outright.

The Queensland University report warned that damage to the reef would cost the economy $6.3 billion and more than 12,000 jobs by 2020.