Cooperative Fish and Wildlife Research Units Program: Wyoming
Education, Research and Technical Assistance for Managing Our Natural Resources

Wyoming Project

Evaluation of factors impacting Kokanee Salmon in New Forks Lakes

August 2020 - December 2023


Participating Agencies

  • Wyoming Game and Fish Department

New Fork Lakes maintain an important recreational fishery for Kokanee Salmon (KOE), Lake Trout (LAT) and other salmonids, and is the primary broodstock for early-run KOE in Wyoming. In recent years, achieving management targets designed to meet KOE propagation needs has proved challenging as several metrics indicate declines in the KOE population. The two primary mechanisms theorized by WGFD are: 1) LAT predation on newly-stocked KOE, and 2) angler harvest of KOE prior to spawning. This project is in collaboration with the Wyoming Game and Fish Department. The goal of this proposed work is to quantify the extent and timing of different sources of mortality (e.g., predation, harvest) on KOE populations in New Fork Lakes. KOE, LAT, and other fish species will be sampled during the open water period using experimental gill nets, midwater curtain gill nets, and hydroacoustics to quantify population demographics (relative abundance, age/size structure), foraging dynamics (stomach content and stable isotope analyses), and indices of condition. These data will be integrated with temperature data and estimates of population size into a bioenergetics model to quantify consumption of stocked KOE by LAT.