MANGILAO, Guam — A third of Guam's coral reefs have died because of rising ocean temperatures, researchers said.
University of Guam researchers said increased temperatures killed 34% of Guam's coral reefs between 2013 and 2017, The Pacific Daily News reported Monday.
About 60% of the reefs along Guam's eastern coast are gone, scientists said.
"Never in our history of looking at reefs have we seen something this severe," said Laurie Raymundo, UOG marine lab director and marine biology professor.
The study was published in the scientific journal Coral Reefs.
The problem is too urgent to ignore because corals are vital to fish habitats, provide coastal protection and contribute to Guam's tourism industry, Raymundo said.
A multi-agency Guam Coral Reef Response team monitors the island's reefs and tries to revive coral communities in line with a 2017 recovery plan. Guam is now in watch status for another mass bleaching event, which precedes large-scale reef death.
"Once we see temperatures starting to rise, this is when we activate our plan," said Whitney Hoot, Guam Bureau of Statistics and Plans coral reef resilience coordinator.
Negative effects could be reduced by making changes in local stressors such as Guam's pollution, sewage system and plastic waste, researchers said.
But elevated global carbon dioxide output is to blame for heightened water temperatures.
"It's what we're pumping into the atmosphere that is creating warmer temperatures," Raymundo said, adding that places with "enormous populations" are contributing the majority of carbon entering the environment. "And it's not small islands like Guam, nonetheless, we are affected by it."
Guam is a territory of the United States in the western Pacific Ocean, about 5,800 miles (9,300 kilometers) west of San Francisco.