Big Bar landslide response information bulletin
August 23 2021
On this page
- Fish attaining natural passage in the thousands
- Enhancement program
- Onsite operations
- Current images of work being done at the landslide site
Fish attaining natural passage in the thousands
Increasing numbers of salmon are successfully migrating past the Big Bar landslide site without assistance this year. As of August 21, more than 308,000 salmon have moved past the slide site. Based on data from the Churn Creek sonar station, the vast majority of these fish are sockeye.
By the end of last week, over 55,000 sockeye were arriving each day at the slide site, including summer-time runs destined for the Chilko, Quesnel, Stellako and Stuart River watersheds. A number of smaller runs are co-migrating through the area. Over the next month, monitoring crews will apply 100 radio tags each week to the sockeye to track their movements. At the same time, further analysis is underway to determine the river volumes at which these fish can naturally pass by Big Bar and if the current large numbers can move through the canyon quickly and without delay.
On August 16, the first pink salmon of the season was observed near Lillooet. Pinks migrate every second year on odd-numbered years, so 2021, 2023, etc. Up to 20% of the Fraser’s pink salmon run migrate past the Big Bar slide site to spawn upstream.
Enhancement program
At DFO’s Cultus Lake Laboratory, Early Stuart sockeye spawning is underway through the end of August, as part of the Big Bar Emergency Conservation Enhancement Program. Reports indicate that the adult fish are in good shape and the egg quality has been very high. A portion of the eggs and milt collected has been transported to the Takla First Nation Hatchery, where they will be used to produce approximately 100,000 fry. These fry will be released into their natal streams in 2022.
The 2021 enhancement program is targeting up to 13 Chinook streams above Big Bar, and two sockeye streams. First Nations fisheries technicians from throughout B.C., local volunteers and DFO staff are currently collecting broodstock from at-risk populations in the mid and upper Fraser regions. Chinook broodstock capture programs are planned around the different run and spawn timings in various parts of the watershed. The earliest timed Chinook return to the Upper Chilcotin, Torpy and Swift rivers, as well as the tributaries within the McGregor watershed. Fish from these systems are being spawned and the eggs are being moved to the Spruce City Wildlife Association Hatchery, Quesnel River Research Centre and DFO’s Chehalis River Hatchery. Other adult capture programs are active in the Chilako, Endako, Willow and Blackwater systems, with more to follow once those are completed.
To build a more robust enhancement program, milt from Chinook males is being frozen and preserved for future spawning to maintain and increase genetic diversity in key populations.
Onsite operations
Crews are gradually demobilizing the Big Bar work site, while the area remains under an evacuation alert due to surrounding wildfires.
The Mckay Creek wildfire has cut access to the West Pavilion Road since July 31. The closure has slowed the transportation of equipment from KM96 to Lillooet and prevented the demobilization of the camp. Primary contractor Peter Kiewit Sons ULC is in daily contact with BC Wildfire Service staff to help guide Kiewit’s operations.
Weather conditions at the Big Bar slide site continue to be hot and humid with the occasional heavy rainfall. Clean-up and environmental monitoring is ongoing during this phase of operations.
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.
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