The escalating level of carbon dioxide in the atmosphere is making the world's oceans more acidic, government and independent scientists say. They warn that, by the end of the century, the trend could decimate coral reefs and creatures that underpin the sea's food web.

In the azure waters of Florida?s remote Dry Tortugas National Park, corals have been toppled by two bad hurricane seasons and blighted by disease and a phenomenon known as bleaching.

Caribbean Sea temperatures have reached their annual high two months ahead of schedule ? a sign coral reefs might suffer the same widespread damage as last year, a U.S. government scientist said Monday.