Most of the Great Barrier Reef has been damaged by coral bleaching

NPR : About 93% of Australia’s Great Barrier Reef has been adversely affected by coral bleaching, according to recent aerial and underwater surveys by researchers at the ARC Centre of Excellence for Coral Reef Studies. Bleaching is a destructive phenomenon that results when corals, which are made up of living organisms, are stressed by environmental conditions and become unable to provide the algae living in them with the nutrients needed to perform photosynthesis. The bleaching event is the worst ever recorded, with just 7% of the reef having escaped bleaching entirely. The northern half has been the hardest hit, with 60–100% of the reef having been severely bleached. Although that area is the most remote and, until now, the most protected from human activities, global climate change has raised the temperature of the water, which has put undue stress on the corals. Whereas some of the damaged corals are expected to survive and regain their normal color, the event is indicative of the wide-scale bleaching of coral reefs that is going on around the world. The long-term effects on those diverse underwater ecosystems remain unknown.