Researchers from the University of Victoria and Parks Canada hope they have found the earliest evidence of human habitation in Canada.

Unfortunately, it lies beneath hundreds of metres of water in the ocean around the Haida Gwaii islands, off the northern coast of British Columbia.

Anthropologist Quentin Mackie and his team returned earlier this month from a research trip to the archipelago, where they used an autonomous underwater vehicle to scan the sea floor in search of evidence of ancient Haida civilization.

Haida Find 20140923

The University of Victoria's Bluefin-12S AUV is shown in Juan Perez Sound with a Gwaii Haanas National Park Reserve vessel in the background. The robot sub scanned the sea floor in search of evidence of ancient Haida civilization. (University of Victoria/Canadian Press)

They can't be certain, but Mackie is hopeful the scans show a stone weir — a man-made channel used to catch fish.

Based on the location, it could date back 13,800 years, when the archipelago was one big island that extended almost to the mainland.

Mackie says a geologist will now study the images to ensure the line of boulder-sized rocks is not a natural formation, and his team will return next summer for further investigation.