The ocean temperatures have risen so high in Florida that one meteorologist compared the waters surrounding the state to a hot tub.

Coral reef coverage off the main Samoan island of Upolu sank to less than 10 per cent due global warming and other local factors in the area, according to findings by researchers published in the scientific journal Marine Pollution Bulletin in April.

Hawaii officials on Thursday proposed a series of steps to fight coral bleaching that's threatening the state's reefs.