News Column

An Ocean of Concern Over Tsunami Debris

June 21, 2012

Sandi Doughton

Plenty of nasty stuff will undoubtedly wash up on Northwest beaches as waves of tsunami debris roll ashore over the coming months, but government officials and independent experts agree radioactive material is not likely to be a concern.

The tsunami that devastated more than 120 miles of Japanese coastline last spring hit hours before the nuclear reactors at Fukushima overheated, leading to a flood of radioactive particles into the air and sea, said Ed Lyman, a physicist and senior scientist at the Union of Concerned Scientists, a group that watchdogs nuclear energy and weapons programs.

"It's unlikely this debris would be significantly contaminated," he said.

The tsunami waves were so fierce that they quickly swept the jumble of homes, vehicles and belongings away from the coast, said Nir Barnea, a scientist at the National Oceanic and Atmospheric Administration (NOAA) in Seattle who is part of a team attempting to track the debris.

However, a University of Hawaii scientist who's also tracking the garbage said strong, local currents probably trapped the floating mass off the coast of Japan for up to a week.

But even so, the garbage doesn't appear to have picked up much radioactive contamination, said the university's Nikolai Maximenko. Volunteers on ships last summer who spotted and collected some of the first debris, including refrigerators and a small fishing boat, measured no unusual levels of radiation from any of the items scanned.

The things hitting the Northwest coast now have been churning in the ocean for nearly 15 months as they made the 5,000-mile journey from Japan.

"Wind, rain and salt spray has been pounding that material for more than a year," said Kathryn Higley, head of the Department of Nuclear Engineering & Radiation Health Physics at Oregon State University. "Anything that was on there is going to have washed off to extremely low, if not undetectable levels."

As a precaution, staff from the Washington state Department of Health are using Geiger counters to scan the Styrofoam, plastic bottles and bigger objects -- including at least one boat -- turning up on the state's coasts. The agency also performed laboratory tests on a few salmon and steelhead collected from the Columbia River and found nothing unusual, said spokesman Donn Moyer.

Albacore tuna off Washington will be tested when the fish return from their migration later this season. Bluefin tuna caught by California sport fishermen five months after the Fukushima meltdowns contained small amounts of radioactive cesium from the reactors. Officials said the levels were too slight to pose a health threat. Also, bluefin tuna migrate near Japan, while the albacore native to the Northwest do not, Moyer said.

Aside from delivering a blizzard of trash to the region's coasts, perhaps the most pressing concern about the debris is the toxic and hazardous chemicals that are certain to be part of the stew. The state Department of Ecology is bracing for reports of barrels stuffed with unknown chemicals, vats of bug killer, bottles of solvents, gas canisters and fuel tanks.

"We don't know what could wash up, when it could wash up or where it could wash up," said DOE spokesman Curt Hart.

Ecology has earmarked $100,000 to help dispose of nonhazardous garbage and is working with coastal communities, Hart added.

Tracking the debris and projecting its route are difficult, NOAA officials said. Within a few weeks after the tsunami, the material dispersed so widely it was no longer visible. Barnea and his colleagues have so far been unable to spot even large pieces of debris, like the floating dock that came ashore earlier this month in Oregon, on satellite images.

The agency plans an experiment off Hawaii this week to see if a small, drone aircraft equipped with a camera might be able to "see" floating garbage scattered in the water by researchers -- who will, of course, gather it all up when the tests are finished.

Lacking actual observations, scientists rely on computer models to map the most likely debris path. Maximenko uses data from floating research buoys to make his model as realistic as possible, and has roughed out a few projections -- with many caveats.

If this year's currents are similar to those in past years, he expects most of the light debris will wind up on the West Coast. Most of the heavier objects, such as lumber and nets and other items that are riding low in the water, will probably bypass the West Coast and be swept south to the gyre between California and Hawaii known as the Pacific garbage patch.

Two expeditions are headed that way to survey areas where debris is likely to accumulate. One group left Japan recently and is surveying the debris field along the way, said Anna Cummins, of 5 Gyres, one of the sponsoring conservation groups.

The second group will sail in July to conduct a similar survey, said Mary Crowley, of Ocean Voyages Institute. Crowley has been working with several Seattle companies to figure out ways to clean up the vast amounts of garbage dumped into the oceans every year.

"We think we can apply the research we've been doing to the cleanup of tsunami debris, also," she said.



Source: (c)2012 The Seattle Times


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