Inside the plan to protect Moosehead Lake from a destructive invasive fish

By Julie Harris, Bangor Daily News Staff

Maine is trying to keep an invasive fish out of the state’s largest lake. The question is whether that is possible.

Moosehead Lake, one of Maine’s most important cold-water fisheries and home to native brook trout and landlocked salmon, already struggles with an increasing abundance of native lake trout plus invasive bass, yellow perch and white perch.

But there is a new threat on the horizon: Northern pike. The fish is a Maine biologist’s biggest fear because pike, along with the other invasive fish species, compete with brook trout and salmon for food. Pike are very adaptable and will eat anything it can fit in its mouth, including its own young. That means the native fish end up smaller and skinnier if there’s too much competition. 

If pike get into Moosehead, they could ruin the landlocked salmon and trout fishery, just as they  destroyed a trophy salmon fishery at Long Pond in the Belgrade Lakes region years ago. 

That would be devastating for Moosehead Lake and the surrounding area, which draws thousands of people from around the world to its waters year-round for lake trout, salmon and brook trout fishing, supporting a multi-million-dollar local tourism economy.

“We really need to dig in and protect [Moosehead]. Once a place has pike, you can’t get rid of it. We have to do what we can to keep them from moving from where they are now,” Tim Obrey, regional biologist for the Moosehead Lake area, said.

But how to do that is the problem. So far, the state has been unable to eradicate pike from waters the fish have infested, partly because by the time a fisherman catches one, the pike are too well established and it’s already too late, according to one biologist. Pike barriers on dams have been successful, but it’s not feasible to install them on inlets and outlets of Maine’s connecting waters.

The likeliest way for pike to reach Moosehead Lake would be through the bodies of water that connect to it. Pike and other invasive fish are skillful at getting through Maine’s water highway to populate new lakes and ponds.

For example, bass come to Moosehead from Jackman via the Moose River, according to Obrey. They established in Lily Bay, Beaver Cove and a few in Spencer Bay, but have increased in number in the last 20 years. They now have breeding populations in the warmer waters of Moosehead and can be found in abundance in Moose River, which feeds into the lake and smaller, warmer lakes surrounding Moosehead. 

There is no bag limit on bass in Moosehead. Obrey couldn’t think of any lake or pond where brook trout and bass thrive together, nor could he recall a place where biologists were able to reduce bass populations by netting them.

“We’re always talking about how to deal with the bass in Moosehead,” said Obrey, while also adding that the brook trout and salmon populations are strong and healthy right now.

But his biggest fear is pike.

There are no known pike between the St. John River, which forms the border between Canada and the United States in northern Maine, and Enfield, which is about 40 miles north of Bangor and is the gateway to the northern end of the Penobscot River. 

But the St. John River has a pike species, the muskellunge, also known as muskie. The lower Penobscot River has pike too, and there is nothing to stop the ones in Pushaw Lake, just north of Bangor, from heading into the upper Penobscot and getting into tributaries that eventually lead to Moosehead, so the potential is there.

Pushaw has a healthy pike population and people go there specifically for that fishery, according to Kevin Dunham, state regional biologist in Penobscot County.

Fishermen have reported spotting a couple of pike at the foot of the dam on the Penobscot River in Enfield and it is possible for the fish to get beyond that point. Black Bear Hydro, the dam’s owner, removed a pike barrier in 2013 to comply with an endangered species permit needed to operate the dam.

Once the dam is breached, pike would have access to the Piscataquis River as well. The pike could conceivably swim to Dover-Foxcroft, where there is a pike barrier. There is no fishway in the dam in the West Branch of the Penobscot, but if pike ever breached it, they could end up in Baxter State Park as well.

There have been multiple efforts to improve culverts for fish passage on streams and either remove dams or install fishways to allow Maine’s native salmon and brook trout into their ancestral breeding grounds and waters. 

A recent example of that is the removal in 2024 of the more than 200-year-old Edes Falls dam on the Crooked River, which now allows salmon from Sebago, one of the state’s four lakes with indigenous wild strains of Atlantic salmon, to reach their native spawning grounds. The Great Works dam on the Penobscot River was removed in 2012, and the Veazie dam, just below it, was eliminated in 2013. Dover-Foxcroft residents voted last June to keep their dam.

The more restoration of access for brook trout and salmon, the more danger there is for allowing invasive fish into the state’s prime fisheries, Dunham said.

Pushaw and Little Pushaw lakes and Perch Pond, also known as Mud Pond, all have pike. They were first found in Pushaw in 2003 and biologists confirmed they were there in 2004. They were found in Kenduskeag Stream in 2011.

Biologists, led by Kevin Gallant, assistant biologist in the Enfield region, plan to do a survey in which they will trapnet about 500 pike from the inlet and outlet of Pushaw Lake and have fishermen report any tagged fish they catch. It will help biologists understand the pike’s movement through the waterways.

Jason Seiders, regional biologist for the Belgrade Lakes area since 2012, knows all too well about pike movement. He describes the territory he’s responsible for as Maine’s pike epicenter.

The Belgrades have been infested with pike since the 1980s, when they were introduced to either North Pond or Great Pond, Seiders said. Only three lakes in that drainage don’t have pike in them because dams stop them. Lake St. George has the best salmon fishery in the Belgrades and is protected by barriers. But there is a new pike infestation in St. George Stream.

Seider said he hoped people would respect the barriers meant to keep pike out of cold-water fisheries, but some would rather the state manage pike as its own fishery and draw more pike fishermen to Maine.

Great, Long and Messalonskee lakes have all been infected with pike for decades, he said. Pike are dense in Sabattus Pond, but there are still large mouth bass in it, too.

Long Pond had an established salmon fishery that the state stocked for sports fishermen. When they began to show smaller sizes and worse quality, biologists investigated and found pike were eating the food. Then the pike began eating the salmon. The last time the state stocked that pond was in 2015 because they were just feeding the pike.

There are no more salmon programs in the three big lakes in that area because of the pike. The state stocks other species in them, such as brown trout, rainbow trout and splake.

“It wasn’t unusual to see pike more than 20 pounds this winter,” Seider said.

For biologists, it’s down to education and outreach since the invasive fish is almost impossible to control. The other part of the plan is to keep them where they are and not let them spread.

“We need to be vigilant,” said Obrey, Moosehead’s biologist.