Technology & Science

Coral reef losses threaten marine life, warn U.S. scientists

Half of all coral reefs off U.S. coastlines are in either poor or fair condition, say scientists who warn that marine life in the Pacific and Caribbean oceans depends on the reefs.

Half of all coral reefs off U.S. coastlines are in either poor or fair condition, say scientists who warn that marine life in the Pacific and Caribbean oceans depends on the reefs.

Garbage, overfishing and water pollution are the main culprits, with reefs closest to urban centres suffering the most.

Researchers with the National Oceanic and Atmospheric Administration sounded the warning Monday at the International Coral Reef Symposium in Fort Lauderdale.

"We need to redouble our efforts to protect this critical resource," NOAA administrator Conrad Lautenbacher said in a release.

The report singled out the threat of coral bleaching, which occurs when the reef is under stress, from increased water temperature, for example, and it releases photosynthesizing algae that live within its tissue.

The algae are responsible for the coral's distinctive colour, and once they are lost, the reef deteriorates.

American coral reefs have been declining for several decades, according to the report's authors. Since the last status report was released in 2005, two species — Elkhorn and Staghorn corals — have become the first ever listed as threatened under the U.S. Endangered Species Act.