F&G releases the first generation of 'captive broodstock' kokanee

About four years ago, a “What if?” idea became reality, and kokanee anglers will soon be catching the results. During June, about a million kokanee fingerlings raised from Idaho Fish and Game’s first “captive broodstock” were released into Idaho’s lakes and reservoirs. Many of those fish will reach catchable size within two to three years.

Traditionally, Fish and Game had captured adult kokanee spawners from the wild and used them for breeding stock to produce the next generation. The new “captive broodstock” program started as an idea from Idaho Fish and Game fisheries staff to help stabilize the number of fingerlings stocked annually.

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. While Fish and Game can't change natural conditions that affect adult survival, hatchery production can buffer some of the fluctuations. 

Taking a cue from the successful sockeye salmon hatchery program, which now produces about a million young sockeye per year, fisheries staff decided to raise kokanee (which are landlocked sockeye) in a similar manner. They raised kokanee to adulthood in hatcheries and spawned those to augment the traditional “trap, spawn and rear” method. 

“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.”

Kokanee typically need consecutive years of favorable water conditions to produce good-to-excellent fishing, and the reverse is also true. A year or two of poor conditions can reduce adult survival regardless of how many fingerlings are stocked. The captive broodstock will help biologists start each year with a consistent number of young fish, so when conditions are favorable, kokanee can flourish. But that can’t occur without a steady supply of fingerlings to stock. 

To start the captive broodstock, eggs were taken from adult fish in the North Fork Payette River in the fall of 2022 and sent to Cabinet Gorge Fish Hatchery in the Panhandle. The eggs were hatched, and the fry reared for a year. Then 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 crews recently released. 

The next three generations of captive spawners are also being raised in hatcheries, and given the positive results of the first crop, fisheries managers are hopeful for they can ramp up to about 3 million fingerlings annually as hatcheries continue to improve their techniques. 

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

Total: 997,943