Washington-based oceanographer Curtis Ebbesmeyer, an expert in tracking ocean flotsam, sent photographs of the floats to the national media in Japan and was told they were authentic. "They were washed out in the tsunami from oyster-grower farms," Ebbesmyer told KMXT.
At least seven black floats have already been found in Washington state over the past few months, Ebbesmeyer announced during a lecture a few weeks ago. (Watch it here.) Ever since a magnitude 9.0 megathrust earthquake struck northern Japan on March 11, Ebbesmeyer and other scientists have been following a massive raft of waste on its slow journey toward North America. The material could ensnare marine life, pollute beaches and possibly include human remains -- or even radioactive material from nuclear power plants damaged during the disaster.
"This is unprecedented in recorded human history to have tsunami debris actually be able to be tracked across the ocean," Ebbesmeyer told KMXT. "We're dealing with an immense event with hundreds of millions of tons of debris on the water. The true dimensions of what's going is probably not appreciated even now."
Peter Murphy, with the National Oceanic and Atmospheric Administration's Marine Debris Division, said that while the NOAA hasn't been able to confirm the floats as being from the Japanese tsunami, they welcome beachcombers and non-government scientists to evaluate unusual items washing ashore on beaches.
Local beachcombers can be helpful in discerning what's out of the ordinary on their beach, Murphy said, since "marine debris is already a significant problem in the world's oceans," making it hard to identify if a piece of debris originated from the Japanese tsunami.
"It's very difficult to fingerprint debris back to its original owner or origin," Murphy said.
The NOAA had created a computer model predicting the way tsunami debris might travel across the ocean, but it didn't show debris going as far north as Kodiak Island. Murphy said that the model represents individual pieces of debris, and the number of variables involved in predicting the path of the debris makes it extremely difficult to predict accurately right away.
He couldn't say whether debris might be making its way even further north, toward the Kenai Peninsula and Cook Inlet or the southern side of the Alaska Peninsula.
"There's a significant amount of variability," Murphy said, adding that information like that obtained from the Kodiak floats and Ebbesmeyer's contributions in confirming their origins are helpful to refine the models.
"The thing with the models is we have the starting location, then additionally the different parameters" for predicting the path of a specific piece of debris, Murphy said. "The more inputs we have, the more weather information that's going to help the models, and as we can get ground truth and verify models, the better they'll be."
To help reach that end, the NOAA has created an email address where people who spot unusual debris that's washed ashore -- disasterdebris@NOAA.gov -- can report what they see. Murphy said to include as much information as possible, especially pictures if they can.
"That will help us better understand what people are seeing," Murphy said.