Since September, there’s been a "dramatic" turn in the tsunami debris washing ashore in the Aloha State, scientists say.

University of Hawaii researchers monitoring that debris say objects such as boats, buoys and lighter materials are being replaced with a steady stream of heavier wooden beams and planks.

The wood appears to be lumber that was used for homes, buildings and telephone poles.

"So far, we have opinions that yes, these objects are from Japan," said Nikolai Maximenko, a senior scientist at UH’s International Pacific Research Center.

The IPRC’s website logs reported debris that comes ashore. Since Sept. 24 it has documented nearly two dozen poles, beams, planks and other wooden building materials washing up at Kauai’s Donkey, Wailua and Hanamaulu beaches and Kailua Beach on Oahu, among other locations.

It makes sense that the heavier wood objects would just be coming ashore now, nearly three years after the tsunami wrecked much of Japan’s eastern coast and claimed thousands of lives, Maximenko said. Lighter and so-called "high-floating objects" harness the wind and currents to travel much faster along the ocean surface. However, the wood objects appearing in recent months are saturated with water and barely rise above the surface — which has slowed their journey considerably, he added.

Maximenko said debris monitors assumed much of the wood swept out to sea by the tsunami sank.

"It catches us almost in complete surprise," he said Friday. "It’s hard to believe that wood can stay afloat for such a long time."

The recent influx of wooden tsunami debris also raises broader questions about potential historical "ecological connections" between Asia and North America, where downed trees similarly could travel across the ocean and carry with them smaller sea animals and vegetation, Maximenko said.

During last year’s Pacific Rim Marine Debris Conference, held at the state Capitol, government researchers said it’s not clear how much of the approximately 1.5 million tons of debris set adrift by the 2011 tsunami remains scattered across the ocean, or where it will wind up.

"We’re just modeling blind," Glen Wata­ba­ya­shi of the National Oceanic and Atmospheric Administration’s Office of Response and Restoration told an audience at the October conference.

Maximenko added Friday that there’s no indication that Typhoon Haiyan, which in November battered parts of the Philippines and claimed thousands of lives, generated any major ocean debris.

Because the storm moved east to west, much of the debris it generated, particularly in the east-facing city of Tacloban, is believed to have been pressed inland instead of out to sea, he said.