Story | 13 Jul, 2023

Spearfishing for invasive fish with Parks Canada

A new technique to protect freshwater ecosystems in Riding Mountain National Park

As the proud steward of a vast network of special places, Parks Canada is responsible for protecting and presenting significant examples of Canada’s natural and cultural heritage. Informed by the best available science, it leads a programme of work to monitor and restore ecosystems, protect and recover species at risk at landscape level, and conducts important research that contributes to our understanding of climate change.

A new technique

Aquatic ecologist Michele Nicholson tells Unite for Nature about one Parks Canada project that is helping manage the impact of invasive fish in beautiful Clear Lake, located in Riding Mountain National Park, Manitoba.

“We’re partnering with local First Nations to try out a new technique for protecting Clear Lake. A couple of years ago we got reports from anglers that they were starting to see and catch smallmouth bass in Clear Lake, and that’s a real concern for us here because they are not native to Manitoba, let alone this lake. They are a really aggressive top predator that eats a lot of other fish.

Michele  Nicholson Michele Nicholson

“Our spear fishing targets bass that are protecting nests

“Local First Nations have fishing rights here, so that’s something we want to protect, and we want to protect the ecosystem in general. Spearfishing has been used in the ocean for controlling invasive fish, but is hasn’t really been explored in freshwater systems, so it’s a really cool project. Our spearfishing targets bass that are protecting nests, allowing predators in the lake to target the bass fry naturally.

“So what happens when this research is done? After we finish the fieldwork, we will do identification of the stomach contents of these fish to determine what they’ve been eating. We’ll send samples away to the lab to tell us how old the fish are, and we’ll be crunching all the numbers and using the information to figure out where we go from here.

“All the decisions will be made collectively with local First Nations. We want to work together to determine the future direction when protecting the health of Clear Lake.”

A video of this project and of other Parks Canada experts in action can be found at Parks Canada’s YouTube channel.