Deep coral reefs in a “twilight zone” in the oceans differ sharply from those near the surface, dimming hopes that they can be a refuge for marine life fleeing threats such as climate change and pollution, scientists said. Worldwide, coral reefs in shallow waters are among ecosystems most threatened by climate change. The Great Barrier Reef off Australia suffered severe bleaching, a whitening driven by warm waters that can kill corals, in 2016 and 2017. A U.S.-led team of divers who studied little-known reefs in the West Atlantic and Pacific Oceans between 30 and 150 meters (100-500 ft) deep where sunlight fades, found most species of corals and fish were unlike those closer to the surface.

Deep reefs no 'twilight zone' refuge for fish, corals. (2018, July 26). The Philippine Star, p. B6.