Idaho Fish and Game is in the midst of a multi-year monitoring effort on trout living in the Snake River between American Falls Reservoir and Gem Lake. This effort, which began in 2019, will determine harvest and catch rates of rainbow, brown, and cutthroat trout, as well as gather information on how well the populations of trout species are doing in this popular fishery.
Ultimately, this information will help Fish and Game biologists understand whether current regulations are working relative to angler interactions.
During sampling efforts over the last two years, Southeast Region Fish and Game staff has worked the shorelines of this stretch of river with a jet boat and electrofishing equipment. When electrofishing, a weak electric current is used to temporarily stun the fish swimming within eight feet of the boat, and then nets are used to retrieve them from the water surface.
Trout were measured for length and weight, and fin rays were taken to age the fish. This information gives biologists an understanding of growth rates and age class structure for trout populations in this part of the Snake River.
Before being released back to the river, fish were implanted with a small tag near the dorsal fin. Each tag is printed with a unique identification number and a phone number to Fish and Game’s “Tag You’re It” hotline. Anglers who catch one of these tagged fish are encouraged to report the tag number whether they harvest or release the fish. This information will determine the harvest and release rates of trout in this reach which in turn helps fish managers develop the best regulations for maintaining a quality fishery.
“We felt it important to do this assessment at this time,” says Carson Watkins, Regional Fisheries Manager for Idaho Fish and Game’s Southeast Region. “This stretch of the Snake River has become increasingly popular with anglers in recent years, and yet few surveys had been conducted here up to this point.”