After avoiding a disastrous season, concern remains for salmon population
KAMLOOPS — The river levels along the Thompson River are on par with the lowest on record, and are currently two metres below their average for mid-October. Despite that, Department of Fisheries and Oceans Salmon Stock Assessment Group Section Head Scott Decker stated mortality rates were actually lower than initial projections.
“We did have some significant mortality of sockeye and other species as they migrated up the Fraser this year, however not at extreme levels or out of the ordinary. We also see a certain degree of mortality and it’s related to flow and temperature,” said Decker.
Due to the challenges presented this season, work was done throughout the region to help the fish migrate upstream, including excavation of Tranquille Creek.
“The river comes out and then it flows across the big sand delta before it enters the South Thompson and Kamloops Lake,” said Section Head Chuck Parken. “The restoration work there was really just to take those channels and bring them back together into a single channel so the water is deeper and that helps the salmon just migrate up for their spawning.’
Parken stated that the low water levels have a large impact on the juvenile salmon and those impacts may not be fully known for a couple years.
“The amount of juvenile Coho and Chinook production is related to the wetted area of the stream and so when there is not a lot of water in the stream area during the summer period, there is not a lot of insect production and food for the juvenile salmon. It really effects their abundance,” said Parken.
With water levels still at historic lows, prolonged multi-year drought is a massive concern moving forward, especially with a potentially drier winter ahead.
“This year we are currently in a fairly strong El Niño, which typically brings warmer and drier weather, particularly in the winter. If we are looking at less precipitation this winter, lower snowpack, we could see a compounding effect of this drought we are seeing this year,” said Decker.