’Dead zones’ a threat to coral reefs

MIAMI: Low-oxygen areas of the ocean known as dead zones threaten hundreds of coral reefs worldwide, fragile ecosystems already struggling because of climate change and pollution, researchers said Monday.

Although dead zones are not typically considered top killers of coral reefs, they may be far more common than previously thought, according to a study in the Proceedings of the National Academy of Sciences, a peer-reviewed US journal.