This Year’s Coral Die-Off on Great Barrier Reef Was Worst Ever Recorded

The Great Barrier Reef in Australia experienced its worst recorded coral die off this year, with one region losing an average 67 percent of its shallow-water coral, scientists confirmed this week. The mass die-off event was caused by abnormally warm water temperatures in the Pacific Ocean, which can trigger corals to expel their algae and calcify and turn white, a process known as coral bleaching. Corals can recover from bleaching, but many never do. “Most of the losses in 2016 have occurred in the northern, most-pristine part of the Great Barrier Reef,” said Terry Hughes, a marine biologist at James Cook University who led the surveys of the coral die-off. “This region escaped with minor damage in two earlier bleaching events in 1998 and 2002, but this time around it has been badly affected.” Damage to the southern two-thirds of the reef, however, was far less than expected, the scientists reported.