High Summer Temperatures Linked to Coral Bleaching

Sep 11, 2019

Researchers from the Department of Land and Natural Resources have observed a coral bleaching event that they link to Hawaii’s record breaking high temperatures this summer.

Maui was most affected by the hot weather. Between May and August, Kahului broke 33 maximum temperature records according to the National Weather Service.

DLNR said the abnormally hot summer was the main contributor to the high ocean water temperature. Waters around Maui were three to five degrees Fahrenheit above normal.

“Warm ocean temperatures are expected to persist in the coming weeks, likely worsening the coral bleaching that has recently been observed across the islands,” Jamison Grove, a National Ocean and Atmospheric Administration Research Oceanographer said in a statement.

DLNR’s Division of Aquatic Resources assessed coral health around Maui where they saw widespread coral bleaching.

Around Molokini, a crater off the Maui coast, 50 percent of the population of a coral species, Montipora capitata were already bleached or heavily paling.

The reefs studied in dirty water closer to the shore at Kalama Park and North Kihei seemed to fare better than those in clean water. The researchers think that the dirty water could be providing shade to the coral, shielding it from direct sunlight.

However, Russel Sparks, a biologist with DAR is hopeful that the reef will be able to adjust to its new environment.

“Natural ecosystems are resilient and they can adapt, they can adjust. We just have to do what we can to give them the space to do that,” he said. “Coral should survive and reefs should continue to adapt and adjust even as other things change as long as we address what we can from local stressors

NOAA and DAR joined Arizona State University’s Center for Global Discovery and Conservation Science to work on reef conservation and study in Hawaii. They released a list of six steps the public can take to help combat coral bleaching.

Sparks explains that one of the main issues DAR is looking to address is the heavy fishing of herbivore fish that protect the reef by eating algae that can cover and kill coral.

People can also contribute by monitoring and reporting their own coral observations to DAR, NOAA and the University of Arizona at hawaiicoral.org.