The Mackenzie River drainage basin is the second largest drainage basin in North America and is sparsely populated. The Peel and Wind River systems flow into the Mackenzie from an almost entirely uninhabited wilderness.
We undertook a canoe expedition down the Wind, Peel and Mackenzie River system. The route started in a region of almost no development (the Wind) where no plastic pollution was expected. The Peel also has virtually no development, but the river does run parallel to the Dempster Highway; recent studies estimate that microplastics from the wear and tear from tires is at least as important as plastic bottles, bags and fibres released from clothing during washing. The Mackenzie, comparatively, has more development upstream including several small villages, wastewater treatment plants and some industrial development around Norman Wells. We analysed samples of water to determine the presence or absence of floating microplastic.
We used conical microfilters, deployed from the bank or canoe, to collect samples daily at 13 locations. We also collected samples from the river channel where sedimentation of smaller particles has occurred. The material collected was examined on site for the presence or absence of plastic particles by eye and using a hand lens. Samples were further analysed on return using a modified smartphone operating as a microscope. GPS was used to record water velocity during sampling and to record all sampling locations. A more detailed methodology is given here.
We started at McClusky Lake, portaging the short distance to the headwaters of the Wind River. From there, we travelled the entire length of the Wind River through the Wernecke Mountains to its confluence with the Peel River. We then followed the Peel River through the lower part of its canyon, on to Fort McPherson and then across the Mackenzie Delta to Inuvik.
We aimed to minimise the impact of the expedition on the environment as much as possible. We did this by: