Another Threat to Coral Reefs: Lack of Oxygen

WASHINGTON - Warming and acidifying oceans are destroying the world’s coral reefs and the diverse ecosystems they sustain. Reef habitats have already shrunk an estimated 30% to 50% since the 1980s, and experts say they could vanish almost completely in the next 20 years.

A recent study points to another threat to the survival of coral reefs: sudden drops in oxygen levels. The study, published in Nature Communications, confirms the observations of scientists working to save coral ecosystems that are home to a large proportion of the word’s marine life. In September 2017, the study’s lead author, coral reef ecologist Maggie Johnson, was preparing to free-dive in the Caribbean waters off the coast of Bocas del Toro in Panama for the Smithsonian Tropical Research Institute’s long-term monitoring program of coastal ecosystems. While sitting on the anchored boat and putting on fins, Johnson saw calm, clear water. But after diving underneath the surface, she and a colleague noticed something very different.