Experts worry about signs of spreading rapid ohia death on Kauai
Rapid ohia death, the fungal blight killing native ohia trees, has been detected at two new locations on Kauai, state officials said.
The fungal disease was first found on Kauai – the first time it had been detected outside of Hawaii island — in May in the Moloa‘a Forest Reserve. Since then, state and federal officials conducting aerial drone flights and helicopter surveys found three more trees on Kauai, which have been confirmed to have Ceratocystis huliohia, the less virulent of the two species of fungi that cause rapid ohia death, the state Department of Land and Natural Resources said in a statement Friday.
The trees were found on privately-owned land in Halelea Moku and near the Lihue-Koloa Forest Reserve. The new discovery places rapid ohia death, or ROD, at three distinct locations on the Garden Isle and at elevations ranging from 600 to 1,600 feet above sea level.
“This new detection is the same species of Ceratocystis found in Moloa‘a where it was evident the trees had been dead for some time,” said Sheri S. Mann, Kauai Branch Manager for the DLNR Division of Forestry and Wildlife, in a news release. “We are finding trees with ROD now because we are searching for them. It’s clear we must be vigilant about doing what we can to stop the spread of C. huliohia and, especially, to prevent the introduction of the more aggressive C. lukuohia.”
The following are five key guidelines to help prevent the spread of Rapid Ohia Death:
>> Keep your eyes open. If you see ohia with a limb or crown turning brown, take a picture, and contact Kauai Invasive Species Committee via email at saveohia@hawaii.edu or call 821-1490. On Oahu, call 266-7994 or email oisc@hawaii.edu, and on Maui, call 573-6472 or email miscpr@hawaii.edu. Samples of the wood must be taken by trained technicians and tested in a laboratory to confirm the presence of the ROD fungi.
>> Avoid injuring ohia. Wounds serve as entry points for the fungus and increase the odds that the tree will become infected and die from ROD. Avoid pruning and contact with heavy equipment wherever possible.
>> Clean gear and tools, including shoes and clothes, before and after entering the forest and areas where ohia may be present. Brush all soil off tools and gear, then spray with 70 percent rubbing alcohol. Wash clothes with hot water and soap.
>> Wash your vehicle with a high-pressure hose or washer if you have been off-roading or have picked up mud from driving. Clean all soil off tires—including mountain bikes and motorcycles—and vehicle undercarriage.
Teams identified a total of 22 areas on Kauai state and private lands with ohia trees showing symptoms consistent with the disease. So far this year, 76 samples have been collected and submitted for lab testing.
Since the first discovery of ROD on Kauai, a team of scientists from state, federal, and private organizations has collaborated to survey the island and develop response plans to the fungal blight. Officials urge the public to be extra vigilant to prevent further spread of the disease.
“At this point, only one of the two fungal pathogens have been confirmed on Kauai,” said Melissa Fisher, The Nature Conservancy’s Kauai Forest Program director. “Now we need everyone to be extra vigilant to prevent further spread of the existing disease and help to keep the other ROD-causing pathogen off our island as well.”
Research partners from various organizations have made significant progress in understanding the disease, including the two different species of fungi and how the fungus enters trees.
Earlier this year, scientists named the two species of fungi that cause rapid ohia death with help from Hawaiian cultural consultants — Ceratocystis huliohia, meaning changes the natural state of ohia, and Ceratocystis lukuohia, meaning destroyer of ohia.
C. huliohia causes a canker disease beneath the bark, spreads slowly, killing off localized areas of water-conducting tissue which eventually causes the tree to die. C. lukuohia, the more aggressive and deadly of the two, causes a systemic wilt, choking off the water supply to the tree quickly, causing the entire crown of the tree to go brown.
Scientists believe the fungi enter trees through wounds caused by clipping, trimming or trampling of roots. Scientists are also investigating the role burrowing beetles play in spreading the fungus.
On Hawaii island, rapid ohia death has decimated hundreds of thousands of acres of mature ohia trees.
A free workshop on how to prevent the spread of ROD will be held from 1 to 3 p.m. Dec. 12 at the Kauai Agricultural Research Station, 7370-K Kuamoo Road in Kapaa. Registration is required at rapidohiadeath.org.
