Document Type

Thesis

Degree Name

Master of Science (MSc)

Department

Biology

Program Name/Specialization

Integrative Biology

Faculty/School

Faculty of Science

First Advisor

Derek Gray

Advisor Role

Co-advisor

Second Advisor

Alex Latta

Advisor Role

Co-advisor

Abstract

The addition of gravel sediment to build ferry landings on the Peel and Mackenzie Rivers has been an ongoing concern for the Gwich’in communities of Fort McPherson and Tsiigehtchic that depend on the rivers for their livelihoods. Specifically, there are concerns that gravel from ferry landings is degrading water quality, harming fishing opportunities, and altering river morphology downstream. Previous reports concluded that ferry operations were not impacting downstream ecology. However, past studies had methodological shortcomings and community concerns about the ferry landings remain. To study the impact of the gravel landings on water quality, I utilized a multidisciplinary study design that included Western Scientific sampling on both rivers in 2018 and 2019, and Traditional Knowledge collection in 2019. During physical sampling, I collected depth-integrated samples of the water column, bed load samples, and benthic macroinvertebrates at sites upstream and downstream of ferry operations. Our team also reviewed existing documentation of Traditional Knowledge and gathered further Traditional Knowledge in Fort McPherson and Tsiigehtchic through interviews and community meetings. As well, I updated and implemented a fish harvest survey in 2019. I found that gravel from ferry landings did not alter turbidity, total suspended solids, or bed load sediments downstream. I observed differences in the abundance and richness of benthic macroinvertebrates but concluded that the differences found were not related to ferry operations. Knowledge holders in both communities expressed concerns that gravel from the ferry landings was contributing to morphological changes on both rivers but also acknowledged large climate-driven sediment inputs upstream (i.e. permafrost thaw slumps). Knowledge holders also expressed a diverse range of concerns that were not considered during the initial design of my study, including: interference with fishing opportunities, ferry cleaning residues entering the rivers, and oil spills. Gwich’in harvesters did not notice changes to the popular fish stocks of Broad Whitefish and Inconnu but harvesters in Tsiigehtchic have been impacted by the physical presence of the ferry landings due to the alteration of traditional fishing locations. My results suggest that ferry landing material is minimally impacting the Peel and Mackenzie Rivers, but ferry operations have interfered with Gwich’in traditional use areas, livelihood, and sense of well-being. Based on these results, I provide recommendations for both the communities and the Department of Infrastructure, Government of the Northwest Territories.

Convocation Year

2020

Convocation Season

Spring

Download

Share

COinS