SALEM — A change in the winds could signal an end to a spike in tsunami debris and other marine trash on Oregon and Washington beaches.
Federal researchers say this year's soggy spring probably aided a noticeable uptick in flotsam along the West Coast, including the northern tip of California.
Some of the debris stemmed from the tsunami that hit Japan in March 2011.
"This is a significant year — 2013 seemed to be a quiet year, comparatively," said Charlie Plybon, Oregon field manager for the Surfrider Foundation, a nonprofit that helps with cleanup.
Winds blowing south during winter months, especially during storms, tend to help push debris toward land. But researchers at the National Oceanic and Atmospheric Administration say the annual transition from wet winter lows to dry summer highs has brought warmer, northwesterly winds that tend to push debris-laden surface water back out to sea.
It's a shift that happens every year between March and June, but Amy MacFadyen, an oceanographer and modeler with the administration, said this year it's a little later and not as sharp as in some recent years.
She said that is why some debris kept rolling in through late May.
"It's a process — it's going to take a little time," she said.
Nir Barnea, regional coordinator for NOAA's marine debris program, said the destruction caused by the tsunami has added to an ongoing problem of marine debris. Material washed away in 2011 may continue to wash up elsewhere for several years, he said.
Last year, construction debris was common, but he said this year there have been a lot of small boats. Not all of them can be traced back to Japan, however.
Among the debris yet to make landfall from Japan may be two more floating docks such as those that washed up in 2012 in Newport, Oregon, and Washington's Olympic National Park.
In March, more than 4,500 volunteers helped clear an estimated 45,955 pounds of debris, including 14 tires, from the entire Oregon coast during one of two annual cleanups organized by the nonprofit organization SOLVE.
Beach-goers can pitch in any time using cleanup bags available at state park offices, said Chris Havel, a spokesman for the Oregon Department of Parks and Recreation.
"Any one person can be their own cleanup crew," Havel said.