A recent report sheds light on the impact of a landslide in the Chilcotin River on the annual salmon migration. The landslide, which occurred last month, has caused significant delays for salmon making their way up the Chilcotin and Fraser rivers to spawn. Although it's clear the landslide has slowed the migration, the full extent of the disruption remains uncertain.
Scott Hinch, a salmon ecologist from the University of British Columbia, explained that the landslide had obstructed the river, impeding the salmon's journey. The debris may also affect how the fish navigate, potentially preventing them from reaching their spawning grounds in Chilko Lake. Current monitoring shows that fewer sockeye salmon are making it past the landslide compared to previous years. Only about 500 sockeye have been spotted upstream so far, compared to the expected 2,664.
The landslide, which occurred at the end of July near Farwell Canyon, around 285 kilometres north of Vancouver, has blocked a critical part of the salmon's migration route. The canyon is a crucial landmark on their journey to Chilko Lake.
Hinch noted that the unstable banks of the Chilcotin River might present further challenges for the salmon. With the river still affected by debris and sediment, it's possible the sockeye run could face additional obstacles as they continue upstream.
In response to the situation, the Tŝilhqot'in National Government has announced a one-year fishing ban on the Chilcotin River's chinook and sockeye salmon runs. This decision aims to protect the dwindling salmon population, which is vital for the Tŝilhqot'in communities. Chief Joe Alphonse emphasized the importance of conserving every remaining salmon, as the species is a crucial food source for the nation.
The fishing ban will require Tŝilhqot'in members to find alternative food sources, such as securing additional supplies from nearby fisheries or turning to ice fishing as winter approaches. Despite the challenges, Alphonse is hopeful that as water flows through the Chilcotin, it will gradually clear the debris and restore a natural path for the salmon.
Jeff Grout, director of salmon management with the Federal Department of Fisheries and Oceans (DFO), stated that it's too early to determine the full impact of the landslide. New monitoring tools have been installed to track the salmon migration. While the salmon run this summer was expected to be smaller than usual, the DFO has not issued fishing licenses for sockeye on this river system.
Sockeye salmon runs typically follow a cyclical pattern every four to five years. This year’s run is primarily composed of offspring from sockeye that faced challenges due to the 2019 Big Bar landslide. Despite the current obstacles, Hinch remains optimistic that the salmon will overcome these difficulties, just as their parents did in previous years.
Researchers anticipate that around 117,000 sockeyes will attempt the journey to Chilko Lake this summer. The true impact of the landslide on the salmon migration will become clearer next week as more sockeye make their way upstream.