DNA research confirms Tsleil-Waututh’s sustainable fishing practices

SFU researchers recommend this Indigenous practice be adopted to mitigate salmon declines

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Thomas Royle in testing lab equipment
PHOTO: Courtesy of Thomas Royle

By: Yelin Gemma Lee, News Writer

SFU archaeology’s ancient DNA lab used their new palaeogenetic analytical techniques to confirm the sustainability and effectiveness of Tsleil-Waututh Nation’s pre-colonial fishing practices. The lab’s research confirms the Tsleil-Waututh Nation was sustainably managing chum salmon by only harvesting male salmon for over 2,000 years. 

The Peak interviewed postdoctoral fellow Thomas Royle to learn more about what he discovered in the lab. 

“The paleogenetic sex identification method we used is the first genetic method ever developed for the sex identification of ancient fish remains,” said Royle. He said although similar methods have been applied to present-day fish, the technique had to be altered to be applied to ancient remains. 

“We applied DNA analysis to salmon vertebrae collected from archaeological sites around the Burrard Inlet. And we used a PCR test to determine if the remains were male or female,” explained Royle. 

He said this study followed the traditional ethnographic record of Tsleil-Waututh knowledge which described “preferentially harvesting male salmon as a resource management strategy.” An ethnography is a written account based on observations of a certain activity or culture. 

According to Royle, ethnographic records showed the Tsleil-Waututh peoples used male salmon’s distinctive visual markers to identify them such as their prominent hook jaws and red-black colour pattern. He learned from the Tsleil-Waututh Nation that they selectively harvested male fish not only because of resource management but also because male salmon are bigger in size and feed more people. 

According to Royle, the research confirmed this traditional knowledge. He said some of the archaeological sites studied date back 2,000 years, showing the deep history of the practice. 

“Looking to Indigenous knowledges, we can see what practices worked in the past and we can implement them in the present [ . . . ] our data suggests that for 2,000 years, salmon were relatively abundant in the Burrard Inlet,” said Royle. “One of the strategies that people seem to have been using to help maintain that abundance is sex selective fishing, so it might be [worthwhile] for the federal government to investigate using it in a modern context.”

Royle emphasized Tsleil-Waututh’s initiation and leadership in this study and how they greatly contributed to the success of this project.

“This study really highlights how by integrating Indigenous knowledge and scientific techniques, we can get a more nuanced understanding of the past. If we just use the scientific technique and just saw there was a lot of male salmon at the site, we wouldn’t really know what that meant [or] what the cultural significance of that was. And without the DNA, we can’t really show this long time frame,” said Royle. 

“Paleogenetics and Indigenous knowledge are often seen as in conflict, but this shows that there’s a way forward through collaboration with First Nations as partners in the research.”

According to SFU News, this research was in collaboration with the Tsleil-Waututh Nation, UBC, and McMaster University “as part of a Tsleil-Waututh Nation project to establish the state of pre-contact ecosystems in Burrard Inlet.” This second paper of the lab’s project can be found published with open-access in Scientific Reports.