An invasive species of fish has been sighted for the first time at Kejimkujik National Park in Nova Scotia, and officials are doing everything in their power to prevent its spread.

Only one fish was found, but that doesn't mean the threat isn't there.

A chain pickerel was caught in a river attached to Kejimkujik Lake.

Chain pickerel are notoriously ravenous, says local angler Reg Baird. They'll eat "anything that swims or moves in the water, even ducklings," he said.

Resource conservation manager Chris McCarthy is shown standing with one of the barriers installed to prevent the spread of invasive species into Kejimkujik National Park. (Stéphanie Blanchet/Radio-Canada)

Chris McCarthy, resource conservation manager at the park, said the fish they found was small, but chain pickerel can grow to about a metre in length.

"One of [the] larger ones was cut open, and they actually found three baby snapping turtles in it," McCarthy said about the species.

The fish are also quick to reproduce, leaving other native species at Kejimkujik at risk.

'We all knew it was going to happen'

In March of 2018, Parks Canada dedicated a budget of $797,000 to try to stop chain pickerel and another invasive species, the small-mouth bass, from getting into an 84-kilometre section of the park.

The fish was found outside of that protected area, but officials are still taking the threat seriously.

"We all knew it was going to happen," said Baird, who has been fishing in the park since 1949. "The whole brook trout fishery at Keji national park is at stake if we have invasive species come in, there's no doubt about that."

Chris McCarthy demonstrates the mesh barrier used to prevent invasive fish from entering the park. (Stéphanie Blanchet/Radio-Canada)

Park officials have installed a net and temporary fence on Peskowesk Creek, which connects five freshwater lakes within the park.

They hope to have a permanent solution by spring.

"If we can put a permanent barrier, there's a chance that invasive fish will not be able to spread in this part of the park," said Jeff Lansing, a spokesperson for Parks Canada. "That way, the native fish species really have a good chance of surviving."

Parks Canada is asking fishermen not to release any chain pickerel they catch. Deliberately introducing the fish into an uninhabited water system is illegal.

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