VANCOUVER _ Fisheries officials say they expect thousands of migrating salmon to pass through an area where a massive landslide hampered them on the Fraser River in B.C. after structural changes to a waterway and lower anticipated flow rates.
They said at a press conference on Wednesday that they were confident that improvements over the past two years on the Big Bar slide north of Lillooet will allow more salmon to reach their spawning grounds this year.
Teams continue to work to clean the Big Bar slide
Michael Crowe of Fisheries and Oceans Canada said chinook salmon are good swimmers and should pass through the landslide without too many problems, but early arrivals of sockeye remain vulnerable in high water.
He said that since the landslide, a protected road to help salmon navigate the landslide area has been built and a separate fish ladder has been built where the salmon will be placed in tanks and trucked to an area. calm after the slip.
“We know the restoration efforts to date are working because we have better crossing conditions than in the past,” he said. “This year is better than last year and last year is better than 2019, so our work is progressing and being successful.”
Salmon should start arriving at Fraser River landslide soon: DFO
Crowe said they hope the nature-like fish pass will handle most of the salmon trying to get through the slip zone, especially large late runs.
“The special populations that number in the hundreds of thousands, and collectively the more than a million that we expect to see this summer.”
However, the future concern is to ensure that the area allows salmon to continue to cross each year, including seasons with high water levels, he said.
The fishway was built to be a protected, slower path that guides the salmon past the landslide area and back to the spawning grounds. Crowe said boulders and boulders were placed over the fishway to create tiny upstream resting areas for the salmon.
Big Bar landslide could mean extinction of salmon runs in British Columbia
The rocks were also placed to reduce the thrust of the tumultuous river, making it easier for the salmon to pass, Crowe said.
The slide in an isolated Fraser River canyon was discovered in June 2019. Over 85,000 cubic meters of rock broke off the 125-meter-high cliff in the river, creating a five-meter waterfall that trapped the salmon below.
Since then, fishworkers and other experts have tried to make it easier to get past the slide by trucking them, building a fish pass, blowing up rocks to widen the channel, and even using the Whooshh Passage Portal System, also known as the Fish Cannon, to propel salmon through a tube past the landslide.
Plans underway for ‘salmon cannon’ to help fish clear landslide in British Columbia
Fisheries officials told a House of Commons committee last summer that the first runs of Stuart sockeye and chinook salmon were wiped out because the fish couldn’t get past the slip zone.
Crowe said up to 18,000 Stuart sockeye are expected in the coming weeks and up to one million sockeye are expected to arrive later this summer.
This report by The Canadian Press was first published on June 23, 2021.
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