Research Spotlight: Tracking Fish to Protect Freshwater Ecosystems

Photo: Celena Brosseau (a fellow MSc. student working with the same telemetry dataset) and Erica Plivelic in the field (Credit: E. Plivelic)

Freshwater ecosystems are under growing pressure from human activities like development, climate change, and pollution. But how do we know when fish are most at risk—and how can we use that knowledge to better protect them?

That’s the focus of graduate student Erica Plivelic’s research, which dives into the hidden lives of freshwater fish in Algonquin Provincial Park. Using a powerful tool called acoustic telemetry, Erica is tracking the movements of five fish species across three lakes over multiple years. These species represent a range of thermal preferences—from cold-water fish like Lake Trout and Burbot, to cool-water species like Yellow Perch and White Sucker, and warm-water fish like Smallmouth Bass.

Photo: Acoustic telemetry receiver download in progress at the field site (Credit: E. Plivelic)

Photo: Acoustic telemetry receivers (Credit: E. Plivelic)

Why does temperature matter? Because a fish’s thermal tolerance affects where it can live and move throughout the year. As seasons change, so do water temperatures, and fish must adapt their behavior to survive. Erica’s research looks at how these seasonal shifts influence habitat use, and how that, in turn, affects their vulnerability to disturbances.

To do this, she’s analyzing habitat metrics like:

• Residence time: how long a fish stays in one area

• Site fidelity: how often it returns to the same spot

• Home range size: how much space it uses on a consistent basis

These patterns help identify when and where fish are most vulnerable—for example, if many individuals are tightly grouped in one area for a long time, they may be more exposed to threats like habitat disruption or pollution. On the flip side, if fish show diverse and flexible habitat use, they may be more resilient to change.

This research doesn’t just look at individual species—it also considers the community level. If all species in a lake are using the same habitats in the same way, the entire ecosystem could be at risk if that habitat is disturbed. But if different species use different areas or adapt in different ways, the ecosystem has a better chance of bouncing back.

Ultimately, Erica’s work aims to inform fisheries management and conservation planning. By understanding when fish are most vulnerable and when they’re most resilient, we can better time development projects and protect the health of freshwater ecosystems for the future.