Lake trout are taking down the numbers of kokanee salmon in Blue Mesa Reservoir, leaving Colorado Parks and Wildlife trying to strike a balance between two species that are both popular with anglers.
The agency is considering an incentives program that will use sports fishermen and women to help trim the lake trout numbers. CPW is seeking public input at Montrose and Gunnison meetings Dec. 18 and 19, respectively. (See details below.)
The proposal is for a harvest-incentive program, to run Feb. 1 - July 31, if approved. Anglers who catch tagged lake trout measuring less than 24 inches could receive a cash prize, be randomly selected via raffle, or for catching the most fish.
Lake trout and kokanee alike are nonnative to Blue Mesa Reservoir.
“In the late 20th century, we really saw a substantial decline of kokanee,” CPW spokesman Joe Lewandowski said. “It was estimated in the early 1990s, we had probably a million kokanee at Blue Mesa. As lake trout kind of started to really take hold, they’re predator fish. The kokanee were basically their favorite prey, and they are voracious.”
The kokanee population, which helps supply 26 other waters in the state with the salmon, has dipped to about 100,000 in the reservoir because of predation and other factors. Yet the spawn take at Blue Mesa is the largest from any water in Colorado. Fertilized eggs and fingerlings are used to stock other lakes, through the Roaring Judy hatchery. The fish hatched there are set into the East River and they swim 20 miles to Blue Mesa, then, following their instincts, they go back up the Gunnison and East rivers to the hatchery, where they are scooped up for CPW’s spawn operations.
“It’s a big source of continuous population. We’re really set up to collect spawn there,” Lewandowski said.
“Most people who go to Blue Mesa to fish look for kokanee because they are tasty. We have a liberal bag and possession limit (five per angler).”
At the same time, the lake is popular with those casting for lake trout, which can reach great lengths and weights; the state record for a lake trout catch came out of Blue Mesa.
“We’re trying to maintain this balance, because we want people to be able to enjoy fishing for the lake trout and we want to accommodate the kokanee anglers too,” Lewandowski said.
“There was a concern if we didn’t do anything, those lake trout would pretty much eat themselves out of house and home. They could take the kokanee way down and then the lake trout don’t have the nutrition to grow into those big, fat lake trout people like, that are trophy-sized. It’s a matter of balancing.”
Anglers’ help is needed because CPW’s netting operation isn’t as effective at reducing lake trout as the sportsperson’s take.
“Anglers are much more effective at taking lake trout than we are setting nets,” Lewandowski said.
Between 2009 and 2017, CPW was catching about 1,200 lake trout annually, compared with the 6,000 or so anglers hooked.
The netting program costs about $40,000 per year; Lewandowski said the agency would prefer to use some of that money for the incentives program instead of spending it to net fish people like to catch.
“We would like to be able to use our anglers to help us with what is really kind of a management plan — how can we harvest more lake trout, maintain kokanee and make sure everyone has the opportunities they want,” he said.
CPW manages the fishery aspects of Blue Mesa, which is a federal water impoundment structure operated by the U.S. Bureau of Reclamation. In addition to lake trout and kokanee, the reservoir is also home to such fish as perch, rainbow trout and brown trout.
“It’s really a healthy fishery. The trick is to try to keep it balanced between the different species,” said Lewandowski.
The lake trout population is robust and the potential incentives program is not expected to cripple the lake trout numbers.
“We do hope we are going to bring lake trout down a bit, but it’s not going to devastate that part of the fishery,” Lewandowski also said.
CPW biologists will fully discuss the incentives program at the Montrose and Gunnison meetings and take input from those attending. They hope to spread the word and hear whether the public thinks such a program would work.
The Montrose meeting is at 6:30 p.m. Dec. 18 at CPW’s office, 2300 S. Townsend Ave. The Gunnison meeting is also at 6:30 p.m., but on Dec. 19, at the CPW office there, 300 W. York Ave.
“We know we can have an excellent kokanee fishery and a trophy lake trout fishery, but we need to continue our work for both species,” Gunnison-based CPW aquatic biologist Dan Brauch said in a news release announcing the meetings and proposed management program.
“ … CPW wants anglers to actively participate in helping manage Blue Mesa and we look forward to hearing from anglers regarding this proposed program.”