Results of annual fisheries surveys on Fresno Reservoir shows high humber of walleye

From Montana Fish, Wildlife and Parks

Montana Fish, Wildlife and Parks staff recently conducted standardized netting surveys on Fresno Reservoir.

These annual surveys take place in September and have been conducted in the reservoir since 1987. These surveys provide important information pertaining to the Fresno fish community and track short- and long-term species trends. The information collected during these surveys aids FWP management of the Fresno fishery.

Walleye were the most abundant species observed, comprising 60 percent of the overall number of fish observed. Walleye relative abundance - the number of walleye observed in each net - in this year's survey was 22.4 walleye/net, which is above both the five-year average - 17.1 walleye/net - and long-term average, dating back to 1987 - 15.2 walleye/net. The average length of walleye observed in 2020 was 14.4 inches, with excellent numbers of 9- to 20-inch walleye.

Another bright spot during this year's survey was the number of yellow perch observed. Yellow perch are the primary forage species in Fresno and are critical to the overall health of the walleye and northern pike populations. Perch also provide recreational benefit to anglers when their population densities are high, especially during the winter months. Yellow perch relative abundance in 2020 was 4.1 perch/net, the highest abundance observed since 2011. The long-term average for yellow perch is 2.4 perch/net.

Northern pike abundance in 2020 was average at 3.5 pike/net, with an average length of 23.5 inches. Other species observed in this year's survey included black crappie, lake whitefish and longnose suckers.

To increase angling opportunity in Fresno Reservoir, approximately 4,000 rainbow trout were stocked in Fresno in June, and an additional 30,000 8-inch rainbow trout will be stocked in October. FWP encourages anglers to "get out and chase these fish this fall and winter."

FWP will begin the planning and development phase of a fisheries management plan for Fresno Reservoir this fall. This effort will solicit the help of an advisory committee to help guide the document. As the plan is developed, there will be numerous opportunities for public involvement, and FWP plans to conduct much of the management planning process virtually.

Please stay tuned for further details, and contact biologist Cody Nagel at 406-265-6177 with any questions.