SANTA CRUZ - The flotsam of the Japanese tsunami has so far included a massive dock, an empty ship and teenager's soccer ball, the latter of which was returned to its owner even as the 16-year-old's family still awaits permanent housing.
Those finds - in Oregon, British Columbia and Alaska, respectively - have affirmed that some of the 5 million tons of debris raked into the Pacific Ocean in the aftermath of a devastating 2011 earthquake are starting to make landfall in North America.
And with some headed toward the California coast, the watch is likely to last for some time.
"It can come ashore over the next several years," said Keeley Belva, a spokeswoman for the National Oceanic and Atmospheric Administration in Maryland, who said scientists believe about 70 percent of the debris sank.
There have been several other unverifiable debris finds, including an empty a bottle of Japanese dish soap found by a Rio Del Mar jogger in March. The speed with which the items have crossed the Pacific Ocean surprised NOAA officials, who revised their models and say items that sit high in the water are being pushed across the sea by winds.
The debris is not radioactive, experts say. The items - ranging from the smallest of trinkets to even automobiles - were pulled in the water by the tsunami and resulting tidal waves triggered by the 9.0 earthquake, days before the Fukushima Daiichi nuclear crisis emerged.
"All of our experts are telling us they don't expect that to be a problem," Belva said.
Locally, Save Our Shores has partnered with NOAA to monitor tsunami debris. In Southern California, Santa Monica-based Heal the Bay is doing the same.
"Save Our Shores anticipates the arrival of tsunami debris on our shores, although how much and when is still uncertain," said Laura Kasa, the group's executive director. "We hope the community will come together and help make sure that the beaches stay clean and safe, whether that's volunteering for our cleanups, notifying us if they find tsunami debris or donating to Save Our Shores to help support more (beach) cleanups."
Both Save Our Shores and Heal the Bay are monitoring lightly used or inaccessible coastal sites to get an idea of how much debris is coming in from the sea. While large items such as the derelict fishing vessel off Canada capture headlines, differentiating between tsunami debris and home-grown trash will be difficult.
"The bigger challenge will be things that break down into smaller bits, and won't be so easily identifiable as tsunami debris," said Sarah Sikich, coastal resources director for Heal the Bay.
Invasive species are another concern. When the massive dock washed ashore in Oregon, Department of Fish and Wildlife officials there scraped and even burned organisms from the structure to keep them from taking root.
But transcontinental shipping has always presented that problem. Ships cross the Pacific Ocean, with creatures catching a ride on hulls or in ballast water.
"(Tsunami debris) is a fraction of what we see in terms of invasive species every day," said Dan Haifley, executive director of the O'Neill Sea Odyssey.
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