The Wyoming Game & Fish Department has stocked Lake DeSmet with kokanee salmon to evaluate if the Pacific fish will thrive and to provide anglers with deep-water fishing opportunities.
Game & Fish stocked 40,000 kokanee salmon in Lake DeSmet in April. The fish are currently only 3.5 to 4 inches in length and were raised at the Dan Speas Fish Hatchery west of Casper, according to Gordon Edwards, Wyoming Game & Fish fisheries biologist.
“We stocked kokanee because we felt that they have a good chance to create an ‘off shore’ or open water fishery,” Edwards said. “They are filter feeders inhabiting the open water of the lake as adults, which gives us hope that they can escape predation by walleye, lake trout, and brown trout in the lake.”
Kokanee are land-locked sockeye salmon. The species originates in the northern Pacific Ocean and can grow to over 2 feet in length.
“Kokanee can create quite a following if they do well. They are really tasty when smoked. I would expect some to reach a size by 2020 for anglers to start catching them through the ice and during the open water season,” Edwards said.
Anglers have seen success by trolling for kokanee using spoons, jigs and flashers. Many sportsmen have also had success fishing for them from shore in the fall when they begin to stage and run the shorelines leading up to spawning, Edwards said.
Kokanee will complete their entire life cycle within Lake DeSmet. Once kokanee reach maturity, the silver color of the fish will change to a deep red, the head will change to a green color and males will develop a large hump on their back and a kype, or large hook on the lower jaw.
“Most will reach maturity at age 4, but a few might try to spawn during their third year as ‘jacks,’” Edwards said. “It is possible that they will find some shoal areas and successfully reproduce in DeSmet, but we will likely need to keep stocking to maintain a fishery. They will definitely run the shorelines in a few years and it is cool to see.”
Game & Fish will also study the density of zooplankton within Lake DeSmet by monitoring the health and growth rate of the kokanee as they age. Zooplankton are small crustaceans that make up kokanee’s diet.
“We hope that there’s enough of these tiny crustaceans that form the base of the aquatic food chain in a lake environment to keep the kokanee fat and growing fast,” Edwards said. “Time will tell and we may need to adjust the number stocked. It’s exciting and we hope it adds something new and fun for people at DeSmet.”