Big Bar landslide response information bulletin

October 16 2020

On this page

• First Nations and DFO release 20,000 Early Stuart sockeye fry from 2019
• Update on fish monitoring
• Ongoing onsite operations
• Current images of work being done at the landslide site

First Nations and DFO release 20,000 Early Stuart sockeye fry from 2019

On October 6, First Nations and DFO staff participated in the release of 20,000 Early Stuart sockeye fry into Gluske Creek near Fort St. James and into Hudson Bay Creek near Takla Landing. The fry were reared from eggs collected from adult salmon that arrived at the Big Bar landslide site during the 2019 migration season.

The release marks another significant milestone for the Big Bar response as the conservation enhancement efforts undertaken during the 2019 emergency response have come to fruition.

As an emergency measure, 177 adult Early Stuart sockeye were collected from the Fraser River below the slide site in 2019. The adults were transported to the Fraser Valley, where they were held until they matured and eggs and milt could be collected. Following a few weeks of egg incubation at Cultus Lake Research Laboratory, the eggs were moved to Inch Creek Hatchery where they were reared until early October 2020. The fry that have just been released will now imprint on creeks, streams and lakes in the Stuart-Takla basin. In spring 2021, they will make the 1,200-kilometre journey to the ocean as sockeye smolts. After two or three years in the Pacific, they will return to the Fraser River and migrate back to the Stuart River watershed, thus completing their life cycle.

Planning for this release was a year in the making and included the collaboration of the Nak’azdli Whut’en, Tl’azt’en Nation, Takla Nation, the Carrier Sekani Tribal Council, Upper Fraser Fisheries Conservation Alliance and DFO. Members of the Nak' azdli Whut'en and Takla Nation performed a blessing ceremony for the survival and safe return of these salmon to their natal spawning grounds.

Some of the lowest returns of the Fraser River sockeye salmon population on record were in 2019 and 2020. A number of factors have impacted these early migrating Fraser River salmon.

In 2019, fish were stalled for a significant amount of time at the slide area while trying to pass the river constriction. They suffered injuries and burned energy reserves. Even the earlier fish that were transported past the slide site had lower survival rates due to their overall poor health condition. In 2020, the unusually high water levels on the Fraser River coupled with the barrier posed by the landslide further impacted the migration of the already struggling early-season sockeye.

The emergency enhancement efforts undertaken in 2019 and in 2020 as part of the Big Bar landslide response are a step towards supporting the long-term survival of vulnerable salmon populations. DFO and Indigenous partners will evaluate the results of these efforts when the adults return to spawn in 2023 and 2024.

While the conservation enhancement efforts are consistent between years, the team has refined and improved its approach based on information gathered through last year's response. For instance, as a result of infrastructure upgrades at the Cultus Lake Research Laboratory, 410 sockeye, including 360 Early Stuart and 44 Bowron were held in 2020 compared to 177 Early Stuart in 2019. Upgrades to hatcheries in Vanderhoof, Prince George, Likely, and the Lower Mainland, expanded the program’s capacity to include chinook salmon.

With the end of the 2020 migration season approaching, planning is currently underway for the 2021 emergency conservation enhancement program.

Update on fish monitoring

Fish are continuing to migrate past the slide site in smaller numbers. as river flows increased from 1,400 cubic metres per second (m³/s) to 2,500 m3/s this past week. As of October 12, 99 of the 122 radio-tagged coho that arrived at Big Bar have passed through the slide. To date, over 161,000 salmon have been detected by the Churn Creek sonar located 40 km upstream of Big Bar.

Ongoing onsite operations

The return of autumn rains is resulting in poor driving conditions at the Big Bar landslide site. Regardless, crews managed to transport components of the Whooshh Passage Portal™ equipment, along with other machinery no longer required for operations to Lillooet.

Additional work this week also included slope monitoring and rainfall management for site safety.

Current images of work being done at the landslide site

Additional images of the work underway as part of our response efforts can be seen on the Government of BC’s Flickr channel.