Sunday, November 2, 2014

People Gotta Move

The University of Victoria's Bluefin-12S AUV is being off-loaded from the Parks Canada vessel Gwaii Haanas II at the end of the project. The team plans to return next summer for further investigation.
Unloading the University of Victoria Bluefin-12S AUV (autonomous underwater vehicle)
There were a couple of interesting underwater discoveries this year in Canada. The one that created the most press of course was the discovery of one of the lost ships from the Franklin expedition in the north but, in my view, the more significant one was the discovery of what is believed to be ancient fish weirs off the coast of Haida Gwaii,  The lost ships of the Franklin expedition were less than 200 years old and the Haida Gwaii discovery is almost 14,000 years old but they both had something in common. In the case of the Franklin expedition men were trying to discover a route to Asia through the waters of the frozen north and, in the case of the Haida Gwaii discovery, it's evidence that people came to America from Asia by way of the ocean.

We have always known the First Nations people in North & South America were of Asian descent but we never really knew for sure how they got here.  Until now the popular consensus was that during the last ice age a land bridge connected Siberia and Alaska and, this area known as Beringia, supported a human population living in an ice free grassland steppe environment that allowed plants and animals to survive.  As the glaciers started to melt 16,000 or so years ago these people were able to move southward over the now exposed landscape and eventually settle throughout the Americas.

In the last ice age, which lasted 26,000 - 13,000 years ago, ice sheets extended to the 45th parallel, which is right around Lincoln City on the Oregon coast.  During this period water was taken from the oceans to form ice sheets up to 3-4 km thick at the higher northern latitudes and caused the global sea level to drop by 110 meters. This, in turn, exposed continental shelves and formed land bridges between various land-masses including Haida Gwaii, which would then have been connected to the present coastline. During deglaciation the melted ice-water is returned to the oceans causing the sea level to rise and, in the case of Haida Gwaii, turned it into an island separated from the mainland by Hecate Strait.

Images of Haida Gwaii 14,000, 12,000, and 10,000 years ago as the ice melted

First Nations oral history claims that people have lived in Haida Gwaii for thousands of years but until now there was little evidence to back this up.  Archeologist Quentin Mackie figured that if people had indeed lived there it would be likely they would have set up salmon fishing sites along the river beds of ancient river valleys that are now under water. Typically these would be stone and wood weirs used to re-direct or trap fish as they move upstream, one of the oldest fishing methods known to mankind.

Ancient river beds (now under water) leading to Juan Perez Sound 
In an area just off of Moresby Island two ancient river beds on either side of Huxley Island leading to Juan Perez Sound in Hecate Strait were identified as possible candidates where evidence might be found of human habitation before the glaciers melted. Using the University of Victoria's AUV (a sort of guided missile with the ability to take sonar pictures) Mackie probed the underwater river beds and discovered a line of rocks which he claims form a fishing weir and are at least 13,700 years old. Interestingly, it was the same person, Alison Proctor, a research engineer at UVIC, who programmed the AUV for both the 2012 Franklin expedition and the Haida Gwaii discovery.

Fish weir illustration

Sonar image of ancient fish weir in Haida Gwaii
Not only does this make it the oldest fishing weir ever discovered, it's also the earliest evidence of human habitation in Canada.  And, while it is extremely gratifying to the present day Haida people to have their ancestral claims finally recognized, it also opens up another debate about how the people got there in the first place. Haida Gwaii is not on the land route from Beringia and the only way people could have got there would have been by boat.

A more detailed examination of the Haida Gwaii site has only just begun and, as the ice continues to melt in the north, more discoveries will doubtless be made there as well. The speculation of course is fascinating as we search for more evidence there were perhaps two routes from Asia to America, and then try to imagine the bravery and determination these people must have had to make the journey, and the circumstances around why they did it, in the first place. Regardless of the route they chose it simply proves that when people gotta move they move.