IDAHO FALLS– Angler groups have been questioning trout safety in Idaho rivers as summer temperatures remain high.

Fears of fish dying from heat are the reasoning behind the groups’ requests that Idaho Fish and Game restrict or close fishing this year. The idea is to reduce fishing-related mortalities to preserve more trout for next year’s fishing season.

While IDFG is concerned about trout deaths due to heat, they believe these fish are resilient, and that the current conditions will not have a long-term impact on trout populations.

“​Wild animals, for the most part, are well equipped to survive fluctuations in environmental conditions, and trout, Idaho’s favorite fish, are no different” said Joe Kozfkay, State Fisheries Manager  “…short-term fishing regulation changes are unlikely to affect their numbers long-term, even during an extraordinary heatwave.”

Kozfkay went on to explain that IDFG biologists understand and share concerns with angler groups that some heat-stressed fish will die from angling-related mortality; however, he notes that basing fishing closures on reducing risk to a relatively small portion of the local trout population will unlikely change the overall numbers in the future.

Although winter seems far off, IDFG says they are more concerned with the cold season’s conditions for fish. Winter is often the most important period for the trout because it is a “filter control” time for the fish. Snowpack and cool water temperatures during winter will allow for IDFG to see how many trout will be available for anglers to target the following year. 

“After a series of good water, temperature, and winter flow years, trout populations increase sometimes to the tune of 30 percent above long-term averages. ”

IDFG said that while they can’t control our snowpack, they can still make “efforts to ensure trout populations are resilient in the face of extreme conditions.”

 IDFG cites their work of restoring habitats, like providing better stream and river channel depths to keep rivers cool, as one way to ensure fish survival. They also remove barriers to allow trout to seek out cold water on their own. 

IDFG hails the department’s efforts as largely effective, but acknowledges there’s “more work to be done to ensure Idaho’s trout have a bright and cool future.”

To learn more visit idfg.idaho.gov.