Ensuring fish are safe to eat in the Canadian north

In 2011, Heidi Swanson’s phone rang. An unfamiliar voice said, “Hi, Heidi? This is George. I heard you work on fish mercury and that you are good at working with communities.”

Eight years later, Swanson and George, who turned out to be George Low, coordinator for the Dehcho Aboriginal Aquatic Resources and Oceans Management program in the Northwest Territories, are planning their seventh field season together.

In the Canadian north, subsistence food fishes such as the lake trout are integral to Indigenous communities, both in terms of food security and culture. However, balancing the health risks and benefits of eating these fish remains a complex problem because northerners are wary of both perceived and real risks of mercury contamination of their lakes and rivers.

Swanson, a professor and researcher in the Department of Biology, has been using a community-centred research approach that is proving invaluable by creating lasting solutions. Northern Indigenous communities are involved in all stages of her research. Together, they ask questions, sample lakes and rivers, analyze results and implement solutions informed by both science and traditional knowledge.

“We fish together, hunt together and cook and live together,” Swanson says. “They teach us about what their traditional foods and land means to them, and we teach them some transferable skills in environmental sampling and community-based monitoring.”

Every two years, Swanson and her colleagues share their results with the communities, where the public is invited to attend and discuss the best ways to act upon key findings.

Swanson and colleagues have identified which fish species contain considerably less mercury than others, therefore safe to eat, and which are very nutritious and high in Omega-3s. Combining traditional knowledge with western science results have also led to a new joint initiative — a “fish-down” in one of the lakes that has higher mercury levels. Swanson and colleagues are hopeful that by catching and removing the largest fish from the lake will decrease the levels of mercury in the remaining fish.

Indigenous peoples in Canada are often faced with unique challenges in terms of their access to safe water and the traditional foods they source from it. As global warming affects the north more acutely than other regions of the globe, it places additional strain on aquatic ecosystems. The issue of water as a human right for Indigenous peoples in Canada will be explored in depth at the University of Waterloo on World Water Day on March 22 as five notable Indigenous women will speak as panelists at the Water Institute’s annual World Water Day.