Geologist tracks driftwood down Mackenzie basin

Geologist tracks driftwood down Mackenzie basin
Natalie Kramer Anderson, a geomorphologist from Colorado State University, has installed six time-lapse cameras on rivers around the NWT, including this site on the Slave River near Fitzgerald, Alta. The cameras are taking photographs every 10 minutes to get a visual of the ice breakup and the driftwood load being carried down the river. Photo by Meagan Wohlberg.

Geologist Natalie Kramer Anderson is exploring uncharted territory in the NWT, but it’s not in search of diamonds or gold. She’s following wood.

The PhD candidate from Colorado State University is testing new research techniques to solve what is currently the unknown mystery of how much driftwood is coming into the Mackenzie River Basin and where it’s going.

“We really do study everything that the water carries,” she said. “We have gauging stations that calculate the volume of water that’s coming through, we measure a lot of the chemistry in the water…We also measure a lot of the sediment load…but we haven’t really ever measured the actual wood that’s coming down, which is another thing a river can carry.”

Anderson was in the NWT in March to install six time-lapse cameras throughout the river basin: one on the Hay River, one on the Slave, one on the Liard, two on the Mackenzie and one on the south shore of Great Slave Lake – a known deposition area for driftwood. She’s also planning on having two more set up on the Peel and the Arctic Red Rivers.

Those cameras are taking photos every 10 minutes in order to catch the ice breakup and the movement of wood downstream over the next three months.

Like the study itself, Anderson’s methodologies – using time-lapse photography and video taken from a kayak on the rivers to measure volume – are previously unexplored.

It’s her hope that the photos will also help her identify relationships between the amount of wood being transported down the river and other factors, like water levels and time of year.

Though the implications may not seem as pressing as those related to a study on the water’s chemistry, Anderson said wood has an extremely important and underrated role in maintaining the equilibrium of river systems.

Anderson (right) and her field technician, Geneviève Coté of Fort Smith, install a time-lapse camera looking out onto a bend in the Slave River before the Cassette Rapids. (Photo by Meagan Wohlberg)

Anderson (right) and her field technician, Geneviève Coté of Fort Smith, install a time-lapse camera looking out onto a bend in the Slave River before the Cassette Rapids. (Photo by Meagan Wohlberg)

“You can think of the wood as a big block of nutrients as it’s coming through the system, so you’re transporting nutrients from the upper basin out to the ocean, and it’s important to know where those nutrients go – if they’re just routed really quickly through the river system or if there’s some feedback along the way,” she told The Journal during a trek to install a camera on the Slave River near Fitzgerald, Alta.

“Decomposing wood provides a lot of nutrients for biodiversity and riparian vegetation along the corridor. Little bugs usually like to eat the wood, and other animals are attracted to these critters.”

As well, once wood reaches the ocean, it plays another important role that people are only just beginning to understand.

“They’ve also found sunken logs in deep oceans – we don’t know anything about our deep oceans – but they find that it’s like a microcosm of life, a hotspot of life right around that one log, because there’s no sunlight down there, there’s no nutrients growing.”

Even people, historically, have harnessed the foreign wood coming downstream for survival in the high Arctic communities, where trees don’t exist, for tools like kayaks, she said.

Anderson said the Mackenzie basin provides a great opportunity for understanding the way wood impacts large river systems.

“What’s really neat about the Mackenzie is we have a really great opportunity to study a system that’s generally intact,” she said. “Not a lot of the forest has been disturbed, so the wood that’s coming down right now is probably very similar to how it’s been coming down since all the forest grew in after last glaciation. So it’s a system that’s very much in some sort of equilibrium – it works.”

What she finds in the Mackenzie, therefore, could have global implications.

“Almost all the large rivers in the world have been extensively altered and dredged of all their wood, so you can’t really get a good estimate of how all these big, huge dams we’ve put up in the world have affected wood output to the ocean, which is part of a system,” she said. “It might not be readily apparent right away, but it’s part of the system.”

For example, wood trapped behind dams on China’s large rivers is hauled away rather than sent downstream, and the effects are starting to be seen.

“People are starting to realize more and more that that wood is really necessary for a lot of bank erosion on the coast lines, so they’re losing a lot of their beaches, their coastlines, because driftwood is no longer on the beaches,” she said.

That’s why Anderson said establishing a baseline in the North is important to do now before the river system is compromised. Such knowledge, she said, will ultimately be just as important for industry to understand as it is for those tasked with protecting the environment.

“For operating a dam, it might be useful information for how much money are you going to have to spend cleaning out from behind the dam when you get these big logs…What if you modelled your dam height so it’s not being overtopped, but you didn’t really take into account what if you have all of a sudden over a couple days…tons and tons of logs?” she said.

“Whether you’re for or against it (hydro) doesn’t matter, you have a responsibility to try to begin to understand how it’s going to affect all the nutrients supplied to the ecosystems downstream.”

Anderson’s research is supported by a grant from the National Geographic Society’s Committee for Research and Exploration and Colorado State University.

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  • […] this summer observing and measuring wood floating down the Slave River for my dissertation work on Mackenzie River driftwood, I attended a local town hall meeting facilitated by Alberta member of Parliament Linda Duncan […]

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