DLNR: Coral Bleaching Not as Severe as Predicted, Still Widespread

An extensive coral bleaching event that has been impacting reefs across Hawaiʻi did not cause as much damage as experts anticipated it would.

The Department of Land and Natural Resources announced today that the situation is now subsiding.

Scientists say warm ocean temperatures during the summer that extended into the Fall led to the recent bleaching.

“While bleaching this year was not as devastating as the events seen across the Hawaiian Islands in 2014 and 2015…there still was substantial bleaching found on all islands,” National Oceanic and Atmospheric Administration representative Gerry Davis said in a press release.

Davis also noted that coral conditions are improving now that sea surface temperatures are beginning to drop.

Reef surveys from the DLNR and NOAA over the past two months indicate that cauliflower and rice corals were most impacted during the mass bleaching.

Biologists found that less coral on Maui were impacted than in 2014 and 2015, but areas left with low coral from previous bleaching were impacted more severely this year.

At a near-shore reef off Pāʻia, which only has 5 percent of its coral cover intact, more than three-quarters of the live coral left were bleached.

Upwards of 50 percent of corals in Molokini Crater experienced bleaching. Numerous Porities corals in Olowalu waters were found bleached and overgrown with turf algae in August.

The researchers reported an average of 40 percent of live coral in many areas along the Kona Coast on Hawaiʻi Island were bleached. Coral in several of those locations died after heavy bleaching in 2015.

According to DLNR, the island-wide reef surveys on Oʻahu were the most extensive their biologists have ever done. Several of the locations on the island were tested for bleaching for the first time.

Bleaching at Lanikai, a beach on the Windward side known for its white sand, covered an estimated 55 percent of live coral. This figure is higher than the percentage reported during the last bleaching event, according to the department.

For reefs at Kāneʻohe Bay, also on the Windward side, bleaching was “patchy.” Scientists say some of the reefs in the area experienced bleaching among about 50 percent of its coral, while 10 to 20 percent of corals were bleached on other reefs nearby.

Reefs off Kauaʻi and Molokaʻi mirrored this yearʻs statewide trend of extensive bleaching in some areas and less in others, scientists report.

In an effort to reduce the effects of bleaching, DLNR launched “The Coral Pledge” earlier today. The six-step reminder aims to inform visitors of preventative measures they can take to avoid harming coral.

“We hope that greater awareness of the constant stresses we all put on our coral reefs and the steps we can take to reduce those impacts, helped the corals persist during this event,” DLNR Chair Suzanne Case said in the release.

“Our efforts to protect, preserve and perpetuate Hawai‘i’s coral reefs as the foundation of the ocean will take knowledge and constant awareness from all of us. The steps outlined in the pledge are the best way for everyone to do their part – simple steps, to save corals.”

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