Time appears to be running out for the treasured corals of the Great Barrier Reef. A 2016 survey of 84 reefs by scientists in Australia found evidence of widespread bleaching at a whopping 93 percent of reefs. They said that 35 percent of corals have already died in the northern and central sectors of the famous reef.
Bleaching is different from actual coral death, and there still may be time for recovery. Bleaching occurs when nutrient-rich algae leaves the coral, causing the colorful animals to turn white. If environmental conditions improve, the coral can come back, but the effects of climate change, which cause abnormally warm ocean water temperatures, are not expected to abate.
A coral reef under siege: