Forecasts from NOAA’s Coral Reef Watch Program indicate that similar warm sea temperatures might occur in the Northwestern Hawaiian Islands, potentially resulting in coral bleaching, particularly to the northwestern most atolls of Kure, Pearl and Hermes and Midway.
However, local weather conditions will strongly influence actual sea temperatures and could either prevent or worsen a mass-bleaching event. Both satellite measurement and in-water instruments have shown current sea temperatures in the monument to be slightly above average, potentially causing a very minor accumulation of heat stress. The highest temperature stress for Papahānaumokuākea Marine National Monument is likely to happen in September.
A research cruise now underway in the Northwestern Hawaiian Islands, as well as one scheduled for September, will provide updates on sea temperatures and coral conditions, and could observe the first signs of a bleaching event.
Bleaching happens when unusually warm water temperatures disrupt the relationship between corals and the microscopic algae that live within their tissues. This stress causes the coral to expel the algae causing a white or “bleached” appearance.
Coral bleaching was previously recorded in the Papahānaumokuākea Marine National Monument in both 2002 and 2004.
Papahānaumokuākea is cooperatively managed to ensure ecological integrity and achieve strong, long-term protection and perpetuation of Northwestern Hawaiian Island ecosystems, Native Hawaiian culture, and heritage resources for current and future generations. Three co-trustees—the Department of Commerce, Department of the Interior, and State of Hawai‘i—joined by the Office of Hawaiian Affairs, protect this special place. Papahānaumokuākea Marine National Monument was inscribed as the first mixed (natural and cultural) UNESCO World Heritage Site in the United States in July 2010.