Coral reefs, already under threat around the globe, may be in particularly acute danger in the waters of Hawaii because of a phenomenon known as bleaching.
The resource makes up less than 1 percent of the underwater ecosystem yet helps to protect 25 percent of marine species, generates tourism revenue and boosts fishing, according to data from The Nature Conservatory.
Many scientists say coral bleaching, which causes a change in color and can result in the eventual death of algae, is but one of the effects of warmer ocean temperatures. That factor that hammered coral reefs near Hawaii in 2014—and may do so again for a second consecutive year.
The warning came from a report this month by the National Oceanic and Atmospheric Administration, which finds that a global coral bleaching event that began last year in the Pacific Ocean may be spreading to the western Atlantic Ocean—and returning to Hawaii.
The potential result could be widespread death of corals and an effect on the "long-term supply" of fish and shellfish, according to the report.
"We are worried," wrote NOAA's Coral Reef Watch lead scientist Mark Eakin in the report, who told CNBC in an interview that bleaching was undermining "a very important source of tourism income" in places like Hawaii.