Thousand-year-old fish bones show native Canadians have fished sustainably by releasing female salmon
A Canadian tribe understood and practiced sustainable fishing for 1,000 years before European settlers destroyed their carefully balanced system with their arrival in the 19th century, according to a new study.
The Tsleil-Waututh nation, which once prospered in British Columbia, used sex selection in fishing to ensure that salmon populations remained robust enough for seasons to come.
Analyzing fish bones from the sites of Tsleil-Waututh villages around the Burrard Inlet, archaeologists found that most of the remains were male.
The researchers said this indicates that they released female salmon back into the water.
“If you take quite a few of the males out of the system, the remaining males can still mate with the females without harming the population,” said lead author Jesse Morin, an archaeologist at the University of British Columbia. The Canadian Press.
“One male can mate with ten females and get the same amount of baby salmon the following year.”
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Archaeologists in British Columbia performed genetic testing on ancient fish bones, some more than 2,000 years old, and found that Tsleil-Waututh fishermen had sex-selected male salmon and discarded the females.
Dating to between 400 BC and 1200 AD, the bones came from four archaeological sites around the Burrard Inlet.
“People were constantly harvesting the same kind of fish, probably from the same places, for 1,000 years,” Morin told the press. ‘Here we are… [after] 150 years of industrial harvesting, and we’ve really destroyed these resources.”
The study was recently published in the journal Scientific Reports.
The Tsleil-Waututh placed large weirs, or partial dams, in the cove to send and then catch salmon preparing to spawn.
Only taking male fish kept stock, as one male can mate with as many as 10 females, the researcher said. Pictured: Members of the Tsleil-Waututh First Nation sailing with Olympic torch for the 2010 Vancouver Winter Olympics
the Tsleil-Waututh fished in the shallows of the Burrard Inlet (above) off the coast of Vancouver Island
The catch would then be landed and sorted, releasing the females.
“I can imagine big traps being set up for these weirs too, so the salmon just swim in them,” Morin said.
“Big wickerwork, and then you just roll those traps down to the beach, out of the river, and then you pull out the salmon you want.”
The researchers analyzed fish vertebrae collected during excavations in the early 1970s using a DNA test to screen for the Y chromosome found only in male fish.
If the Tsleil-Waututh had just randomly collected fish, the male-female split would be closer to 50-50.
This is the first time the technique — called a polymerase chain reaction or PCR test — has been used on ancient fish remains, study co-author Tom Royle, a postdoctoral candidate in archeology at Simon Fraser University, told the paper.
Humans came to British Columbia at least 14,000 years ago, but Europeans didn’t begin to visit the area until the 1750s.
By the mid-1800s, the Hudson Bay Company had established trading posts and the Vancouver Islands were colonized by the British.
An example of a weir used by the Vancouver Island Quamichan
A subsequent gold rush brought even more Europeans to the region, destroying the Tsleil-Waututh barrages and starting a process of overfishing that, combined with climate change, has had a devastating impact today.
Nearly all species of Pacific salmon are in decline, and half of the Canadian Chinook, some of which still spawn in Burrard Inlet, are listed as endangered, according to the report. the guard.
This upsets the environmental balance and threatens the killer whales and grizzly bears that prey on Chinook.
In order to rebuild the stocks, the press reported, some members of the Tsleil-Waututh have refrained from fishing on their traditional territory, even though they have treaty rights to do so.
The Tsleil-Waututh are just one of many Coast Salish Nations in the Pacific Northwest who have developed advanced and sustainable fishing methods lost with the arrival of western settlers.
The explorers exposed indigenous coastal communities to disease and forced them out of their culture and land.
In 1863, 30,000 natives — or 60 percent of British Columbia’s native population — died from smallpox brought to the area by an unsuspecting San Francisco miner, according to macleans.
The decimation of local tribes in the century after first contact, leading to loss of knowledge, skills and techniques.
Last month, archaeologists reported that wooden posts in the shallows off Vancouver Island, which had puzzled historians for years, are the latest evidence of hundreds of ancient fish traps placed there by the K’ómoks people between 1,300 and 100 years ago.
The traps are said to have provided food security for up to 12,000 K’ómoks, the traditional inhabitants of the Comox Valley.
The sticks had been a mystery to archaeologists and even to the modern K’omoks community.
Archaeologist Nancy Greene spent months recording the locations of the exposed piles, which range from thumb-sized in the shallows to the size of a tree trunk in deeper water.
The remains of more than 150,000 sticks are uncovered during low tide in Canada’s Comox Estuary (pictured), off the coast of Vancouver Island
She recorded 13,602 exposed piles made of Douglas fir and red cedar, but predicted there would have been between 150,000 and 200,000 that would form the core of 300 traps in the shallow wetland, according to to Hakai magazine, one of the most extensive and advanced indigenous fishing activities ever recorded.
The traps were arranged in two styles — a heart-shaped and a chevron-shaped trap — which were lined with a removable panel of woven wood that let water in, but not let the fish through.
Archaeologists found the stake is what remains of hundreds of ancient fish traps placed there between 1300 and about 100 years ago by the people of the Canadian First Nation
When the tide came in, herring and salmon flocked to the center and when it receded they were stranded, ready to be collected by K’ómoks fishermen.
According to Greene, they only took enough fish with them to meet their trade and food needs, without depleting the total supply.
If a spawn rate looked weak, the tribe would choose not to fish that season, according to K’ómok’s oral testimony, allowing them to reproduce.
HOW THE OLD FISH TRAPS WORK
The old fish traps are based on a thorough knowledge of the behavior of fish and the large tidal differences in the region.
They are classified in two styles, a heart-shaped and a chevron-shaped trap.
They were lined with a removable panel of woven wood that let in water, but didn’t let the fish through.
As the tide rose, the fish rushed to the center of the trap, which was designed to mimic the shoreline they would flow through.
When the tide receded, the fish stranded in shallow pools of water.
They worked to catch herring and salmon, even allowing longtime stewards to manage the spawn rate in local creek systems.
This allowed them to ensure that they only took enough fish to meet their needs — for trade and food — without hurting overall stock levels.