HONOLULU: Corals at remote atolls northwest of the main Hawaiian islands suffered some bleaching this summer as ocean temperatures rose to higher than normal levels for a couple of weeks.
Corals expel the algae they rely on to survive when the ocean becomes too hot. This makes them appear white.
Thirty percent of the Kure atoll reef and one-fifth of the Pearl and Hermes atoll reef bleached.
But corals were spared the large-scale mass bleaching observed in Indonesia and other parts of Southeast Asia this year.
Scientists who returned to Honolulu on Wednesday from a monthlong research trip to the area say it`s unclear if the bleached corals will recover or die.
The Northwestern Hawaiian Islands are home to 69 percent of U.S. coral.