‘Once rich with coral and sea life, 90 percent of the Great Barrier Reef today is composed of large swafts of bleached white or dead coral. Warm seas off the coast of Queensland, Australia, killed some two-thirds of a nearly 500-mile stretch of coral in 2016 after warm water caused the coral to expel living algae, triggering it to calcify or turn white, a process known as bleaching. Researchers have called it the worst die-off of coral ever recorded at the reef.’
Source: Climate Change Has Already Devastated the Great Barrier Reef