British Columbia

No timeline for opening of natural passage for salmon bottleneck on Fraser River

Officials say they're working as quickly as possible but can't determine if they're on track to create a natural passage at the site of a Fraser River landslide that would allow salmon to reach their spawning grounds.

40,000 fish, mostly chinook and sockeye have been counted since measures put in place

Crews are using portable hydraulic rams and airbags, chippers, drills and small, low velocity explosives to further break the rocks and create the passageways. (Chris Corday/CBC)

Officials say they're working as quickly as possible but can't determine if they're on track to create a natural passage at the site of a Fraser River landslide that would allow salmon to reach their spawning grounds.

The slide discovered last month created a five-metre waterfall in a narrow and remote portion of the river near Big Bar north of Lillooet, B.C.

Al Magnan, environmental lead for the team working to help the fish pass, says conditions change every day so crews aren't working on a timeline.

Millions of fish are expected to reach the site in the coming weeks and Magnan says 40,000 of primarily chinook and sockeye have already been recorded two kilometres downstream from the barrier.

He says crews have transported 1,400 salmon by helicopter but few have been recorded passing the site on their own.

If more fish don't begin making it past the slide site, officials say a fish ladder to help salmon move up the waterfall is ready for installation on the weekend or early next week.

Crews rappel down the rock face to remove loose rock to stabilize the area where the slide happened. (Chris Corday/CBC)

Mass die-off not imminent

While there appears to be a bottleneck of fish building downstream, Magnan says that doesn't necessarily mean there will be a mass die-off.

"From a migration point of view, it's never linear. There are natural delays in migration and natural barriers that take time," he said.

Analysis of the slide shows it likely occurred in October or November.

A number of salmon species migrate up the river to spawning grounds, including chinook, sockeye, pink and coho.

Work on the swift-moving river in the remote area is challenging and crews continue rock scaling to make it safer.

On Monday, they worked to clear roughly 300 logs that had accumulated in a back eddy immediately downstream of the waterfall to clear the way for a fish wheel.

The wheel being assembled onsite is one of many strategies biologists are pursuing to capture and move the salmon.

Comments

To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.