Algae and an oyster are among the clues Oregon biologists believe may link the vestiges of a sea-ravaged boat that washed up on a state beach Tuesday to the devastating 2011 tsunami in Japan.

Five years after Japan's magnitude-9.0 earthquake set off a series of massive tsunami that demolished a swath of its Pacific coastline and killed nearly 20,000 people, debris — and sea creatures — from the disaster are still finding their way to the Oregon shore, said Chris Havel, a spokesman for the Oregon Parks and Recreation Department.

"That kind of habitat attracts living animals even if it's floating out in the ocean," Havel said. "We should not be surprised to continue to see debris from Japan wash up on the shores."