This article discusses the impact that climate change is having on fish and fishing.
Salmon and trout anglers across the Pacific Northwest are going to have fewer places to fish over the next 40 years, concludes a new study published this month.
Scientists at the Forest Service’s Rocky Mountain Research Station in Boise found that in the summer and early fall, rivers in the Pacific Northwest have already warmed 1.8 degrees Fahrenheit since 1976. That’s the same rise measured at the Bonneville Dam over the last 80 years and used in models by climate scientists.
The researchers studied 391 monitoring sites. The temperature pattern gives them confidence the warming trend is going to continue for the next 40 years, said Dan Isaak, the lead researcher. That means salmon and trout are going to have less habitat, and will be replaced by warm-water fish like smallmouth bass.
The study — “Global warming of salmon and trout in the northwestern U.S.: Road to ruin or path through purgatory?” — was done after the 2015 season, when warm temperatures in the Columbia, Snake and Salmon rivers killed off nearly all of the sockeye salmon returning to Idaho’s Sawtooth Valley. The research shows that sockeye, which migrate during the heat of the summer, are going to be exposed to lethal temperatures in rivers from 5 to 16 percent longer during their trip. For Redfish Lake sockeye, the exposure will be 30 times what coastal sockeye face.