Coral Bleaching Near Oahu Signals Ecosystem’s Distress

With this summer bringing record-breaking heat waves throughout the northern hemisphere, the people of Hawaii have found that the lack of trade winds have made for a particularly warm and humid summer. And they're not the only ones suffering.

Researchers docked at the Heeia Small Boat Harbor in Kaneohe, who spent the weekend checking the health of nearby reefs, indicated Monday (Oct. 6) that the higher-than-normal ocean temperatures may be causing the mass phenomenon of near-shore coral bleaching in reefs surrounding the islands. As corals are symbiotic organisms that rely heavily on the food provided by photosynthetic algae living within them, the warm water which prompts algae to leave poses a great threat as corals begin to starve and die. And according to officials at Hawaii's Department of Land and Natural Resources, the bleaching that crews are discovering along Oahu's windward coast are particularly severe.

"It is fairly common to see some level of bleaching around this time of year" marine resource specialist with the department, Anne Rosinski says. "But this is way above average from what we would expect."

The problems lie in the heat, the department says. With this past September being the second-hottest on record since records began in the 1940s, with underwater temperatures reaching as high as 86 degrees, they are seeing that roughly 75% of the dominant coral species surveyed in Kaneohe Bay are showing signs of the bleaching process. And the reports don't end there. There have also been new reports of coral bleaching on Maui, the Big Island and at Honolulu's famous Hanauma Bay.

Facing warming waters, on top of environmental stresses such as pollution and human disturbance, the coral species are simply not healthy enough to resist bleaching. And the distress signal is being taken very seriously by local conservationists.

"The Corals are animals, right, they're not rocks" Hawaii's Director of Marine Programs for The Nature Conservancy, Kim Hum says. "So what bleaching is, it's a sign of distress."

"[We need to] make our corals as healthy as possible... so that they can respond and they don't bleach and die because of these additional stressors."

And what they're praying for right now is the return of the trade winds, which in turn will cool down underwater temperatures and allow the corals to rebound again.