The area of mortality of ohia trees from a fast-spreading fungus has grown by half over the last year on Hawaii island, the state Department of Land and Natural Resources said Monday.

The good news, based on aerial surveys, is that the disease known as rapid ohia death has not spread to the other islands, the department said by email.

“Rapid ohia death continues to spread at an alarming speed,” Philipp LaHeala Walter, state resource and survey forester, said in a statement. “It appears the original outbreaks are increasing in size and the disease is moving north along the Hamakua Coast.”

The aerial surveys are supplemented by ground surveys, since the fungus is only one of several diseases that can kill ohia, he said.

Trained surveyors assessed more than 780,000 acres — 82 percent — of the state’s ohia forest during the most recent helicopter surveys, DLNR said. On the Big Island surveyors spotted an additional 26,000 acres of forest where ohia trees had brown leaves or none.

That’s added to more than 48,000 acres identified in the July 2016 survey, for a total of 75,000 acres affected by the disease.

The Legislature has provided $1.5 million for the next two fiscal years for the continuation of surveys and other initiatives aimed at stopping the spread and identifying the disease’s cause.

Rob Hauff, with the Division of Forestry and Wildlife, said, the quarantine imposed by the state Department of Agriculture on the movement of ohia wood and plant materials between islands is helping prevent the spread of the disease to other islands to other islands.

MAUI

Rainfall highs posted

Five gauges across Maui County recorded record rainfall last month, the National Weather Service reported last week. Four other locations posted their highest totals since 1989, the Maui News reported.

The gauge at Haiku logged 13.19 inches in April; Pukalani had 8.98 inches; Waikapu had 8.72 inches; the Kaunakakai Mauka gauge recorded 3.35 inches; and Lahainaluna had 2.25 inches. Except for Lahainaluna, the totals were at least double the average.

Meanwhile, Ulupalakua Ranch recorded 10.33 inches; Kula Branch Station, 8.10 inches; Kahului Airport, 7.77 inches; and Molokai Airport, 6.54 inches — all the highest totals since 1989.

An especially wet second half of the month contributed.

“It was mainly because you had two storm systems that came through,” said Kevin Kodama, senior hydrologist with the weather service.