A fishing boat lost during the Japanese tsunami disaster a year ago has turned up off Canada's west coast.

The 65-metre vessel was first spotted on Tuesday last week by a Canadian Forces aircraft on a routine surveillance patrol, but an aerial inspection has since suggested there was no-one on board.

A military photo shows the ship, streaked with rust but intact, floating 278 kilometres off the southern coast of Haida Gwaii islands, some 1,500 kilometres north of Vancouver.

Transport Canada says its Japanese owner has been notified and it is considering it an obstruction to navigation.

It also says the vessel is being monitored for pollution.

The ship is the first and largest item confirmed to have crossed the Pacific Ocean to North America from Japan's devastating earthquake and tsunami on March 11, 2011.

Near Midway Atoll in the deep Pacific, a Russian ship spotted an intact 20-foot Japanese boat from Fukushima last year, along with debris such as a television and other household appliances, the University of Hawaii said.

Ocean researchers based in Hawaii are monitoring the debris from the tsunami, which they earlier predicted would reach western North America early next year.

There have been reports of Japanese bottles and other items washing ashore, but it is not clear if they were from the tsunami.

Earlier this month, Canada's western province of British Columbia and the western US states of Washington, Oregon and California signed an agreement to coordinate management of the tsunami debris when it reaches shore, and to return items of sentimental value to Japan.

The Japanese fishing boat that was found this week is not expected to reach landfall for another 50 days, said a media statement by Washington Senator Maria Cantwell, who has a special interest in marine issues.

AFP