Australia's Great Barrier Reef experiencing worst bleaching on record

Often dubbed the world's largest living structure, the Great Barrier Reef is a 2,300-kilometre (1,400-mile) long expanse, home to a stunning array of biodiversity including more than 600 types of coral and 1,625 fish species. "The cumulative impacts experienced across the reef this summer have been higher than previous summers," the federally funded Marine Park Authority said in a statement. This event is the fifth mass bleaching on the reef in the past eight years. The Reef Authority's chief scientist Roger Beeden said climate change posed the biggest threat to reefs globally.