Following Successful Lake Trout Suppression, IDFG For First Time In 6 Years, Resumes Kokanee Stocking In Payette Lake

For the first time since 2014, Idaho Fish and Game has stocked kokanee salmon into Payette Lake in McCall. Hatchery staff stocked a total of about 400,000 kokanee into the lake in late June, and will continue to stock that many kokanee every year until at least 2024.

Resuming kokanee stocking follows two years of successful lake trout suppression efforts, which IDFG fishery managers are using to restore Payette Lake’s status as both a trophy lake trout fishery and kokanee destination.

Managing the Payette Lake fishery is a challenge that IDFG fisheries managers have been wrestling with for some time.

Lake trout are big, long-lived predators and kokanee, their primary prey in Payette lake, are a short-lived and fluctuating species. Balancing these two very different populations is tricky, but it’s crucial to their goal of maintaining viable fisheries for each species.

Starting in the early 2000s, lake trout began to dominate the fishery, which resulted in a seriously suppressed kokanee population and, because of the lack of their primary prey species, much smaller and thinner lake trout. Fisheries managers ceased stocking kokanee in 2014 due to poor survival of stocked fish, and began evaluating options to bring the fishery back into balance.

In 2018, fisheries managers began intensive lake trout suppression with specially designed gillnets, the same as those used for lake trout suppression in Upper Priest Lake in northern Idaho. In 2018 and 2019, IDFG removed over 1,400 Lake trout from Payette Lake. The suppression effort primarily targeted smaller, younger fish, leaving the larger, older fish for anglers to continue to catch in the popular lake trout fishery.

A few years into the project, surveys of lake trout are already showing positive results. Lake trout body condition has improved slightly, which indicates there is now less competition for forage, so fish are growing fatter. In 2019, the number of kokanee salmon that were naturally spawning in the North Fork Payette river above Payette Lake increased three-fold compared with the prior 10 years of monitoring, demonstrating increased survival.

“This is encouraging, but it’s not where we want to be yet,” said Jordan Messner, regional fisheries manager. “We’re still a ways off the mark from spawner returns in excess of 40,000 individuals in the mid-1990s. In any case, it appears conditions are now more favorable for increased kokanee survival, and we resumed stocking in 2020.”

The ultimate goal is to reestablish a self-sustaining kokanee population that is in balance with the lake trout population, but anglers pursuing both species could reap the benefits of the stocking in the short term. The kokanee stocked this year should reach catchable sizes for anglers in two years, and lake trout enthusiasts can expect bigger, fatter fish thanks to a more abundant prey species.

To continue to improve conditions for kokanee survival, IDFG says it is committed to continuing Lake trout suppression efforts annually through the current Fisheries Management Plan period (2019 – 2024), along with annual stocking of 400,000 kokanee fingerlings. Continual annual monitoring of lake trout and kokanee abundance, lake trout body condition, and stocked kokanee survival will provide IDFG managers with the information necessary to determine the next steps in the management of the Payette Lake fishery.

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