Prior to European colonization, the indigenous communities of the Pacific Northwest practiced sustainable fishing techniques for thousands of years. A recent collaboration between scientists at Simon Fraser University and the Tsleil-Waututh nation revealed how these Coast Salish peoples maintained a sustainable chum salmon (Onocorhynchus keta) fishery 2,000 years ago (Robitzski 2021).
A team of scientists and archeologists from the university designed this project for the Tsleil-Waututh nation to validate historical records from the Port of Vancouver. Using PCR techniques, scientists were able to extract the DNA from salmon bone samples (Figure 1) that had been collected from four different historical sites along the northeast coast of Vancouver (Morin et al 2021). They discovered that at two of the four sites, the bones were overwhelmingly male. The other two sites had a more balanced mix of male and female salmon remains.
With just the raw DNA data, it was at first unclear whether this uneven distribution of sexes was intentional or not. So, the university scientists then turned to members of the Tsleil-Waututh Nation to better understand the nation’s historic fishing practices. These members confirmed that the Coast Salish inhabitants did prefer male salmon, because they were larger and provided more food (Robitzski 2021). Furthermore, these fishermen could easily distinguish between the sexes due to the coloration and large front teeth of males (Figure 2).
Together, the scientists and Tsleil-Wauthuth nation concluded that this data suggests male salmon were also selected because of the sustainable benefits. It is likely fishermen realized that male fish can fertilize the eggs of multiple females, so fishing selectively for males would not deplete the overall salmon population. Therefore, the Coast Salish peoples were able to sustain a healthy chub salmon fishery.
With the current world human population on the never-ending rise, overfishing continues to become a pressing issue. It is key that we continue studies like this one in order to learn from the sustainable practices of our ancestors.
Citations
Morin, J., Royle, T.C.A., Zhang, H. et al. Indigenous sex-selective salmon harvesting demonstrates pre-contact marine resource management in Burrard Inlet, British Columbia, Canada. Sci Rep 11, 21160 (2021). https://doi.org/10.1038/s41598-021-00154-4
Robitzski, Dan. (2021, November 29). 2,000-year-old salmon DNA reveals secret to sustainable fisheries. The Scientist Magazine®. Retrieved November 30, 2021, from https://www.the-scientist.com/news-opinion/2000-year-old-salmon-dna-reveals-secret-to-sustainable-fisheries-69466.