Severe thunderstorms developed rapidly near the South Fork of the Salmon River Aug. 6, and within minutes, heavy rain pushed large amounts of sediment into the stream, choking it. Idaho Department Fish and Game fisheries managers are now assessing damage to the summer Chinook stocks.
According to a news release, sediment flowed into holding ponds at the South Fork Salmon trapping facility, depriving the fish of oxygen. Fish and Game and Nez Perce Tribe workers rushed tanker trucks to the facility to save as many Chinook salmon as they could, but they were only able to save about 200 adult salmon. An estimated 1,200 Chinook were lost.
"Broodstock losses will significantly impact the number of eggs for the IDFG McCall hatchery program and the Nez Perce Tribe's Johnson Creek program in 2014," said Sam Sharr, an anadromous fisheries coordinator. The Johnson Creek Artificial Propagation Enhancement Program
spawns wild and hatchery-reared salmon together in central Idaho, helping salmon populations reach healthy numbers.
With this loss however, significantly less adult Chinook will return to the South Fork of the Salmon River in 2018—as summer Chinook typically fulfill a four-year cycle, returning from the ocean to where they were spawned four years earlier.
Surviving fish were transferred to the Rapid River Hatchery near Riggins. Fishery managers will spawn them there over the next several weeks, trying to mitigate the impact of the loss. Managers at the trapping facility are now working with tribal representatives to minimize the impact of wild Chinooks in the South Fork drainage.