Invasive chain pickerel outnumber native fish at Kejimkujik National Park

Kejimkujik National Park is grappling with an ecological crisis as invasive chain pickerel have surged in number, threatening native fish populations. Once dominated by brook trout and yellow perch, the park's lakes and rivers have seen a dramatic shift since the chain pickerel's arrival in 2018.

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They are quite good at what they do. It’s an invasive species because they reproduce quickly, they move quickly, they’re actually the top predator in our watersheds right now.

"They are quite good at what they do," said Gabrielle Beaulieu, an ecologist with the national park. "It’s an invasive species because they reproduce quickly, they move quickly, they’re actually the top predator in our watersheds right now." Beaulieu explained that the fish "outcompete a lot of the native species, both for food and shelter throughout the park, as well as outside of the park."

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And they outcompete a lot of the native species, both for food and shelter throughout the park, as well as outside of the park.

The latest Kejimkujik Angler Diary Report highlights the extent of the problem, showing over 5,300 chain pickerel caught compared to 5,006 brook trout and just under 4,000 yellow perch. Last year, the situation was so severe that nine out of 10 fish caught were chain pickerel, forcing the park to suspend its brook trout creel census to avoid stressing native species.

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Unfortunately, because chain pickerel has now essentially taken over a lot of the populations of fish in the waters at Kejimkujik, we felt it necessary to reduce any potential stress that we would be putting on native species of fish.

Introduced to Nova Scotia in the 1940s for sport fishing, the chain pickerel population has since exploded. Sheri MacNeil of the Nova Scotia Invasive Species Council warns that the fish have already impacted trout and could spread to other watersheds if not managed. The province enforces a catch-and-kill policy, and while the chain pickerel are easy to spot, vigilance is key to preventing their proliferation in new areas.

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They have impacted the trout and it will happen in other watersheds in other areas if we don’t try to prevent the spread.