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Experts consider best way to free salmon trapped below Fraser slide

Incident command post set up to tackle the fish passage problem from Lillooet
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Extreme turbulence at the site of the rock slide in the Fraser River near Big Bar is blocking fish passage.

Finding the best way to release salmon trapped by a landslide in the Fraser River near Big Bar is under careful consideration by experts.

Fisheries and Oceans Canada and B.C. government officials announced Friday at a technical briefing that they are working together to address impacts of the June 23 slide at a remote and unstable part of the Fraser River.

An “incident command post” was set up at Lillooet with several agencies working in tandem to find the best remediation options.

Options and remediation now being considered:

• Take no action and continue to monitor fish passage;

• Explore options to remove rock obstruction; or

• Physically move the trapped fish upstream.

“Each of these options come with potential benefits and some risk or possible risk of consequence. For this reason, we continue to thoroughly assess each option,” according to the update July 7.

What they believe happened was that a massive slab of rock sheared off and slid into a steep and narrow section of the river, creating a five-metre waterfall and a barrier to fish passage.

Several types of fish are being impacted based on the “magnitude” of the obstruction, including some of conservation concern, officials said. The fish stocks include: Interior Fraser Steelhead (Chilcotin), Spring/Summer Chinook, Interior Fraser Coho, Early Stuart Sockeye, Early Summer Sockeye, Summer Run Sockeye and Fraser Pinks.

Dean Werk, president of the Fraser Valley Salmon Society, said he appreciates the unified approach to the problem that officials are taking by working together, but “decisive action” needs to be taken quickly to help the fish.

“This truly should be considered a state of emergency for this historic wild salmon and sturgeon river,” Werk said. “The early wild salmon population is predicted to have a dire run this season and every salmon needs to reach its natal stream in the first part of the migration.”

The swift-moving water is impeding salmon and other fish from migrating upriver to reach spawning grounds, but they also created hazardous conditions for responding agencies at the site, which is not accessible by road. Field staff were forced to conduct an assessment of the site from the safety of a helicopter over the weekend. They used water dropped from a helicopter bucket to sluice away some of the sediment at the site.

If the decision is made to capture and move the fish away from the blockage, several capture methods could be used. The use of nets and weirs was discussed at the joint briefing on Friday, as well as beach seining. The fish could be transported on a flat-bed truck, to be re-introduced to the watercourse, or transported by other means such as a helicopter.

The Fraser Valley Salmon Society has been at the forefront of conservation of wild salmon and sturgeon for more than 34 years, Werk said.

“Our members and the world are very concerned about what has happened,” he said.

The hope is that as many fish as possible can be released from the obstruction.

“The least impact on wild salmon the better, but if there is a loss of a small amount due to clearing the slide, then we may need to sacrifice these fish, to have the largest portion of the runs of sockeye and chinook reach the spawning areas safely,” Werk said.

There is a chance of about 7.9 million mid-summer sockeye due to return, he estimated, judging from the outgoing fry potential from four years prior.

“We are hopeful this will be resolved so that all user groups can have opportunities for the future,” Werk added.

Some fish are getting through, like the larger chinook, but it’s a relatively small number in the context of the total number of fish trying to pass.

“What has happened up near Big Bar obviously is of great concern to all of us, to all British Columbians,” said Federal Fisheries Minister Jonathan Wilkinson, at a separate salmon restoration funding announcement on Friday alongside provincial officials.

“We are working on it expeditiously because of the fish there waiting to pass,” Wilkinson said.

The minister acknowledged the barrier is a threat for First Nations who rely on the salmon for their food and ceremonial purposes but it’s also a threat for the commercial and recreational fisheries.

“The Fraser as you know is the most important salmon-bearing river in B.C.”

He said they were looking at “all options” to dislodge the obstruction.

READ MORE: Slide blocked fish

READ MORE: Fraser unsafe but fish could be moved

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Geotechnical engineers and other experts have been assessing the slide site on the Fraser River north of Big Bar. (Submitted)


Jennifer Feinberg

About the Author: Jennifer Feinberg

I have been a Chilliwack Progress reporter for 20+ years, covering city hall, Indigenous, business, and climate change stories.
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