About a million kokanee fingerlings raised from the Idaho Department of Fish and Game’s first “captive broodstock” were released into Idaho’s lakes and reservoirs in June, including Hayden Lake and Lower Twin Lake, the agency announced Thursday.

Many of those fish will reach catchable size within two or three years. 

The new “captive broodstock” program started as an idea from fisheries staff to help stabilize the number of fingerlings stocked annually, according to Fish and Game. 

“Raising and rearing fish for anglers is nothing new for Fish and Game because we’ve done it for over a century, but this is a new twist that we think will benefit kokanee anglers,” said Beau Gunter, Fish and Game’s state hatchery production manager. “Within about four years, our fisheries and hatchery crews have taken it from a concept to young kokanee being released, which included raising the captive broodstock from eggs to adults.”  

The agency has traditionally captured adult kokanee spawners from the wild and used them for breeding stock to produce the next generation. Fish and Game tries to stock around 7 million kokanee fingerlings every year, but a bad year for adult survival can affect how many fingerlings are available the following year. 

Hatchery production can buffer any fluctuations. For example, the agency’s successful sockeye salmon hatchery program now produces about a million young sockeye per year, according to Fish and Game. 

Taking a cue from that program, fisheries staff raised kokanee in a similar manner. 

The captive broodstock started in the fall of 2022 with eggs taken from adult fish in the North Fork Payette River. The eggs were sent to Cabinet Gorge Fish Hatchery in the Panhandle. The eggs were hatched and the fry reared for a year. 

About 15,000 young kokanee were transferred to the Grace Fish Hatchery in southeast Idaho and reared two more years to spawning age. Their offspring are the fingerlings that crews recently released. 

Here’s where the first generation of captive broodstock fingerlings were stocked: 

• Anderson Ranch Reservoir — 66,934 

• Arrowrock Reservoir — 201,217 

• Deadwood Reservoir — 53,505 

• Hayden Lake — 82,200 

• Lower Twin Lake — 25,200 

• Lucky Peak Reservoir — 134,052 

• Montpelier Reservoir — 8,715 

• Payette Lake — 247,084 

• Ririe Reservoir — 179,036 

“The development of a kokanee captive broodstock will greatly improve our ability to manage kokanee in Hayden Lake,” said Andy Dux, regional fishery manager for the Idaho Department of Fish and Game. 

Kokanee fishing in the lake is almost entirely supported by hatchery fish, Dux said. In recent years, it’s become more difficult to secure eggs from wild populations that are best suited to doing well in Hayden Lake. 

“When that has happened, we’ve had to substitute eggs from populations that don’t perform as well,” he said. 

The captive broodstock approach should provide a much more consistent source of eggs from fish that do perform well in the lake, according to Fish and Game. 

“Hayden Lake is one of the most popular kokanee fisheries in the region, so more reliable stocking will benefit anglers in the coming years,” Dux said. 

The next three generations of captive spawners are also being raised in hatcheries, according to Fish and Game. As hatcheries continue to improve their techniques, fisheries managers hope to ramp up to about 3 million fingerlings annually.