The department is seeking public input on fishing regulation changes to address declines in brown trout. Input will be used by the department to develop regulation proposals for the commission to consider at its August meeting.
Due to growing public concern regarding brown trout declines in some popular SW Montana fisheries, the department is considering fishing regulation changes for select waterbodies. The department has seen continued declines in brown trout abundance in several rivers. Although each river has unique population drivers, there are some common trends.
Over the past year, the department has been working with the U.S. Geological Survey to compile long-term fisheries data from 41 fisheries monitoring sections in 14 rivers. Results will help evaluate fisheries trends with large-scale variables that may be influencing brown trout populations. Although full analysis is not complete, preliminary results suggest that flow is a primary limiting factor for many brown trout populations. The department continues to analyze these data and explore other potential causes of brown trout population declines.
Since all the evaluated fisheries are managed as wild trout fisheries (no fish are stocked), the department has a limited set of tools to manage these populations. The department will continue to work with water users and agriculture producers to improve flows during critical times and improve habitat where possible, but these efforts take time. As such, anglers on several rivers are requesting the department implement regulation changes to act in the short-term.
Short-term trends have shown reduced numbers of small, juvenile brown trout in the Big Hole River, Ruby River, Boulder River (tributary to the Jefferson), Beaverhead River, upper Yellowstone River, Madison River, and upper Stillwater River (tributary to the Yellowstone). Currently, these are the primary waterbodies where the department is considering regulation changes. Depending on public input, the department may implement regulation changes to entire rivers or may change sections of rivers to evaluate effectiveness of regulation changes.
Listed below are potential fishing regulation changes that the department is considering. On their own, none of these proposed changes are expected to drastically improve brown trout population abundance; however, each may reduce some stressors to the population during critical periods.