A 54-metre-long fishing vessel that was set adrift after last year's devastating earthquake and tsunami in Japan has been spotted off the coast of British Columbia. No one is aboard the vessel, Canadian officials say.

An airline contracted by the federal government first spotted the rusting ship last Tuesday about 140 nautical miles off the southern tip of Haida Gwaii, formerly known as the Queen Charlotte Islands.

The vessel has been identified as coming from Hokkaido, Japan, and officials say it is drifting very slowly towards shore.

"A vessel this size, I'm surprised it took so long because it's so exposed to the wind," oceanographer Curtis Ebbesmeyer told CTV News.

The Canadian military said there is no sign the ship is leaking fuel. A warning has been issued to other ships in the region because the vessel poses a potential navigational hazard.

Transport Canada said five federal departments are monitoring the situation.

As much as five million tonnes of debris were swept into the ocean when a massive magnitude-9 earthquake and resulting tsunami struck Japan in March 2011, killing nearly 19,000 people.

Scientists predicted that debris from the disaster would make its way across the Pacific Ocean to the North American coast.

Last fall, material began washing up on B.C.'s West Coast – from plastic bottles to more personal items such as babies' clothing and toiletries, all bearing Japanese lettering. A Tofino resident began cataloguing the material in an archive.

At the time, Tofino Mayor Perry Schmunk told local media that he found the discoveries both eerie and sad.

One beachcomber found a helmet that resembles those worn by Japanese rescue workers.

"It's just debris, but it's bad for the environment and bad for marine life," environmental scientist Menas Kafatos told CTV.

In early December, a Japanese fishing float was found in Neah Bay on Washington State's northwest tip. It was thought to have come from an oyster farm in the stricken area.

However, other scientists cautioned that the material discovered last fall wasn't necessarily related to the tsunami. They predicted that Japanese debris won't hit North American shores until 2014 at the earliest.

With a report from CTV News' Roger Smith