Oceanographer and consultant Curt Ebbesmeyer in Seattle told the Victoria Times-Colonist such things as fishing boats, small freighters and possibly even houses and other buildings were being carried by ocean currents towards the British Columbia coast.
"We just finished running a simulation with a drifter, a buoy that got lost in the area of the tsunami, and we find that the first of the debris would be here now," he told the newspaper.
The 33-foot tsunami hit Japan's eastern coast after a magnitude-9 earthquake March 11.
Ebbesmeyer said the debris field in the Pacific Ocean is about the size of California and its outer fringes are nearing British Columbia. The bulk of the debris isn't expected to arrive until 2014, he said.
The researcher asked beachcombers to photograph anything they find washed ashore and send the pictures to his Web site at www.flotsametrics.com.
The International Pacific Research Center in Hawaii is also tracking the debris movement. There, researcher Jan Hafner told the newspaper the majority of the seaborne wreckage will be trapped in a swirling North Pacific "garbage patch."
He said a cargo ship's crew has reported seeing an 18-foot Japanese boat in the debris field.