ROBERT SIEGEL, HOST:
From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel in Washington.
MELISSA BLOCK, HOST:
And I'm Melissa Block in Southern California.
Farther north, up the Pacific Coast, beaches are now getting a regular dose of debris from last year's tsunami in Japan. The first few items were curiosities - a boat here, a soccer ball there. But as the litter accumulates, it could create some real issues. Here's Washington State Governor Chris Gregoire.
GOVERNOR CHRIS GREGOIRE: We are in for a steady dribble of tsunami debris over the next few years. So any response by us must be well-planned and it will be.
BLOCK: As NPR's Martin Kaste reports, beyond the obvious litter problems, officials are on the lookout for hidden dangers.
MARTIN KASTE, BYLINE: The tsunami swept an estimated five million tons of debris into the Pacific Ocean. Japanese scientists guess about 70 percent of that sank right away, which leaves maybe a million and a half tons still floating around.
CAREY MORISHIGE: It's everywhere. It's spread out across nearly the entire North Pacific Ocean.
KASTE: Carey Morishige is the Pacific Islands coordinator of the Marine Debris Program at the National Oceanic and Atmospheric Administration. She says they can't just track the debris from above - it's too hard to see. So they use computer models to predict its movement.
MORISHIGE: All marine debris does not move the same. It depends on what the particular item is. If it sticks above the water quite a lot, winds tend to move the items faster.
(SOUNDBITE OF WAVES)
KASTE: And that's exactly the kind of objects that are now littering the beaches at Ocean Shores, Washington. Bev Hughes has been picking up plastic bottles.
BEV HUGHES: I think they all clearly have Japanese writing on them.
KASTE: Also on the beach is Lynn Albin. She works for the state and she's here to check the debris with a Geiger counter. She holds it up to the bottles.
(SOUNDBITE OF BEEPING)
KASTE: Radiation levels are normal and that's what state officials expected to find. Most of the radiation from the crippled Fukushima Daiichi nuclear plant was released after these objects had already been swept out to sea.
But some Japanese debris may carry another kind of threat. Earlier this month, a 65-foot-long floating dock washed up near Newport, Oregon.
JOHN CHAPMAN: Felt like looking at a spaceship or something. It was an island that had drifted across from Asia.
KASTE: John Chapman is a biologist at Oregon State University, where he specializes in invasive species. And that's what he found on the dock. Among the dozens of species that hitched a ride, at least three are possible threats: a sea star, a Japanese shore crab, and Undaria pinnatifida.
That last one is the edible seaweed you found in Miso soup, but Chapman says if it started growing here, we might not be able to eat our way out of the problem.
CHAPMAN: If you have mountains of Undaria, it's useless, right? It's bad. You're playing roulette. Every time you putting a species into a system, it could take over.
KASTE: People assume the ocean is a big mixing bowl - that species drift back and forth all the time. In reality, Chapman says, shoreline species usually don't find a way to get across the Pacific. But the combination of the tsunami and manmade objects like docks and floats meant that Japanese species got a rare chance at a ride to the West Coast.
He says the result may be an unprecedented threat of biological invasion. And that's why Oregon officials decided not to take any chances with that dock.
CHAPMAN: The consensus of everyone, and I'm not sure where that started, was kill them as quick as you can and as dead as possible. So they scraped it down and then they took blowtorches and burned the surface.
KASTE: Chapman says the torching may have seemed a little excessive, but he was OK with it, given the risks.
Martin Kaste, NPR News, Seattle. Transcript provided by NPR, Copyright National Public Radio.