British Columbia study shows sustainable management of salmon fisheries before colonization

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A new study confirms what Michelle George’s family has told her about her Tsleil-Waututh ancestors’ fishing practices of targeting male salmon both for meat and to sustain fishing.

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They knew that if “more females come upstream to spawn, the circle of life will have a better chance of succeeding,” said George, a technical and cultural specialist at Tsleil-Waututh Nation off the shores of Burrard Inlet in North Vancouver.

The study, published Wednesday in the journal Scientific Reports, examined chum salmon bones dating back to 400 BC. C. and 1200 d. C. of four archaeological sites around the cove.

He then used a polymerase chain reaction or PCR test to detect the Y chromosome, which would indicate that the fish was male.

The test found that the bones of the male fish markedly outnumbered the females at two of the village sites, whereas something closer to a 50:50 ratio would be expected if the fish were collected at random, Tom Royle said, one of the co-authors of the study. .

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The study marked the first time the genetic technique was used on archaeological fish remains, said Royle, a postdoctoral student at Simon Fraser University.

The results highlight the success of the Tsleil-Waututh approach to fishing, as the abundance of salmon in Burrard Inlet was stable for at least 1,000 years, said Jesse Morin, Tsleil-Waututh Nation archaeologist and adjunct professor at the University of British columbia Institute of Oceans and Fisheries.

“People have been collecting the same kinds of fish constantly, probably from the same places, for 1,000 years,” he said. “Here we are, 150 years later, 150 years of industrial harvesting, and we have really destroyed these resources.”

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Oral histories from Tsleil-Waututh tell of people using landfills to catch salmon as fish made their way from the ocean to freshwater spawning grounds, Morin said.

“I imagine big traps set up for these dumps too, so the salmon just swim in them. Big wicker traps, and then you just roll these traps onto the beach, out of the river, and then pull out the salmon you want, “he said.

“If a good number of males are removed from the system, the remaining males can still mate with the females without detriment to the population,” he said. “A male can mate with 10 females and have the same number of salmon next year.”

The Tsleil-Waututh dams were toppled with European colonization, Morin said.

At the two sites where the study found a more even distribution of male and female salmon bones, Morin speculated that people had to use a different collection method that may not have been suitable for selective focus.

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“Maybe it’s just those two villages that show that male biases have access to the prey, right? They’re fishing in the dam in the Indian River and maybe other people are in other little streams and ditches here and there without selectivity, ”he said.

The study used salmon bones that had been stored at Simon Fraser University since they were collected during excavations in the early 1970s, added Morin, who searched the collection for samples from specific times and places.

The vertebrae tend to be the best preserved salmon remains, Royle noted. Off the coast of British Columbia, he said, fish remains can be preserved quite well, as many indigenous ancestral sites contain shells, creating alkaline conditions that fight acidity.

In recent years, George said Tsleil-Waututh members have chosen not to exercise their fishing rights in an effort to help rebuild salmon populations that are declining to record lows from the impacts of climate change, the loss of habitat and collection.

She said she hopes the nation can use the study to showcase their long-standing skills and give them “a better foot to stand on” in conversations with Fisheries and Oceans Canada about how fisheries are managed in their territory.