News & Views Breeding Hatchery Operations
Idaho fish bags award for hatchery trout study

Idaho Fish and Game biologists have been awarded the Outstanding Sport Fish Restoration Program Projects of 2023 by the American Fisheries Society’s Fisheries Administration Section for its hatchery trout study.

With raising and stocking hatchery trout being expensive, the researchers worked on improving the stocking program, investigating whether stocking larger trout benefits anglers and is cost-effective. 

The biologists tagged tens of thousands of hatchery rainbow trout before stocking them and checking with anglers to see how many were caught. They, then, compared angler catch rates of two sizes of rainbow trout: standard size (10-inch) and “magnum” (12-inch). Feed costs were also compared in the hatchery to raise a 12-inch trout than a 10-inch trout.

“Idaho has a long history of using research to improve our hatchery trout stocking program,” said Beau Gunter, the state’s fish production manager, in a press release. “The ‘magnum’ trout program is a great example of how we integrate research into our stocking program to make fishing better while making our operations more efficient.”

Idaho’s trout stocking program includes 10 hatcheries and raises over 17 million fish annually, with about 1.5 million being “catchable”-size rainbow trout. 

The research uncovered that hatchery managers could offset the increase in food costs by raising fewer, but larger trout, and anglers would benefit by catching larger and more fish, despite the lower number of trout stocked. 

Despite the cost of magnum trout being 31 per cent more in feed than smaller trout, anglers caught 100 per cent more of the larger trout than the smaller ones. 

The results of the study are changing the way fish and game raise hatchery trout as hatcheries like the Nampa Fish Hatchery have already shifted trout production entirely to magnums.