Anglers, Biologists Working Together

Cooperation is a wonderful thing, especially when two groups that don’t always see eye to eye work toward a common goal.

- Jordan Weeks

Since 2006, I have worked closely with several avid musky anglers to mark and recapture muskellunge in a number of local waters. This work uses PIT (Passive Integrated Transponder) tags to develop population metrics for muskies in waters that may be difficult to sample by traditional means.

The most difficult waters to sample are riverine systems, including reservoirs. The open nature of these systems makes capturing muskies very difficult because they continually enter and leave them via upstream rivers or downstream migration through a dam or barrier. This movement is termed immigration (entering the system) or emigration (leaving the system).

In Wisconsin, most population surveys take place in the spring. This is when many of our major game fish spawn and can be found congregated in predictable areas — except rivers and some reservoirs. Muskies in reservoirs, along with walleyes and other species, often make significant upstream movement in the spring, leaving the reservoir to spawn or feed in the upstream watershed. Unpredictable hydrological conditions in rivers make them nearly impossible to survey effectively.

You can imagine how difficult it might be to count fish in a water body when you have no idea how many fish are entering or leaving, not to mention how many might be dying or being born each year! It’s a monumental task.

Scientists continually work to try to find new ways to estimate population metrics, and therefore better manage fisheries. At the end of the day, anglers want the same thing!

Researchers in Ohio worked with anglers to supplement fisheries mark-recapture data to better manage a stocked population in Clear Fork Reservoir.