Since the early 1980s, waterways across central and southern Maine have been significantly altered by the presence of the invasive northern pike.
Once the northern pike is introduced, there is little management that can be done as the fish has no major predators. But while the presence of northern pike brings about immense ecological implications, some fishermen are embracing them.
It's a sunny morning, and Nate Bergeron of Lisbon is out fishing on Sabattus Pond.
"Got one. Little guy. He's a biter though," he says. "It's a pike!"
Bergeron has been fishing in this shallow, man-made pond for nearly two decades, and he says he loves catching pike.
"That's the thing that draws me here, is the chance for a bigger fish. Pike do get very large," he says.
Growing up to 40 inches long, northern pike are carnivorous — with elongated bodies and large mouths full of sharp teeth.
But while pike excite some fishermen, they're also aggressive, capable of devouring other fish, frogs, and even small mammals. With a voracious appetite for native species like salmon, northern pike can alter entire ecosystems.
Take the case of Long Pond in the Belgrade Lakes region. For nearly a century, it was one of the state's most prominent landlocked salmon fisheries. And then in the 1970s came the illegal introduction of northern pike. That means someone obtained the invasive fish, transported them, and secretly dumped them in the watershed.
"When northern pike were introduced into this system, they quickly went to the top of the food chain and caused a crash of the forage base and then the landlocked salmon themselves," says Jason Seiders, a fisheries biologist with the Maine Department of Inland Fisheries and Wildlife.
Seiders says that the northern pike not only attacked the salmon but also ate their primary food source: rainbow smelts. By 2015, the there were so few surviving salmon, it was no longer possible to fish for them.
"So now we basically have to manage around these fish, and like I said, they grow really large, larger than our native species and much quicker," Seiders says.
In response, the state agency introduced the more resilient rainbow trout to Long Pond, to provide a fishery for anglers. But other illegal introductions followed and pike were able to invade other central and southern bodies of water where they once again climbed to the top of the food chain.
Now, the closest salmon fisheries are in western and northern Maine where Seiders say they too are vulnerable to the introduction of pike.
"We don't want to see them spread to especially northern Maine because of all those intact native trout fisheries that we have up there. But really the only tool we have is education and outreach to try to explain to folks, you know, the dangers of introductions of these fishes. There really is no silver bullet to stop this. And like I said before, once these fish are in there, they're in," Seiders says.
Northern pike are notoriously difficult to eradicate. The state of California was able to do it with the use of chemicals, But it took multiple shocks to the lake and cost tens of millions of dollars.
"If you can't get rid of them all, all you're doing is buying time," says Scott Davis, a state biologist with the Maine Department of Inland Fisheries and Wildlife who's stationed in the Belgrade Lakes region. From his boat, he says chemical reclamation is risky to other species and it also requires public support.
"All it takes is one person to go back and buy pike off the internet if that's what they do and re-introduce them again," Davis says.
Scott Fyfe of Sabattus points out that Sabattus Pond is too shallow to ever support a cold water fishery. And he says the pike have attracted anglers and boosted the local economy. He thinks the state should manage the pond as a sports fishery and make the best of the situation.
But that idea has been rejected. Instead, biologist Davis says,the focus should be on educating the public on the dangers of illegal introduction and preserving the fisheries in the North.
"We're going through generations now that don't even know what the Belgrades were for its landlocked salmon fishery, and they see the northern pike fishery as always being there and a great big fish to catch. People really enjoy catching those large fish. However, what they're doing is forgetting about what it was," Davis says.
According to the Maine Department of Inland Fisheries and Wildlife, northern pike are confirmed to be in 39 lakes and ponds, placing other native fish in all of those areas at risk.
Support for Deep Dive: Invasives is provided by Maine Audubon, Friends of Acadia and Coastal Maine Botanical Gardens.