Nonnative smallmouth bass can now be found at Grand Falls on the Dead River. Credit: Courtesy of Bob Mallard

While most Maine conservation non-profits are focused on habitat, the number one threat to our wild native fish is nonnative fish introductions, not habitat degradation. To be fair, while dams are the primary cause of the decline in endangered Atlantic salmon and other anadromous fish, nonnative fish introductions have compromised more inland native fish populations than anything else. Unlike dams, most of which were constructed generations ago, many nonnative fish introductions are relatively recent events, and it is still happening.

Highly invasive smallmouth bass can now be found throughout the Kennebec River system from Brassua Dam on the lower Moose River and Grand Falls on the Dead River, all the way down to the ocean, including Moosehead Lake, Indian Pond, Wyman Lake and tributaries such as Spencer, Enchanted and Austin streams, as well as West Outlet, Sandy and Carrabassett rivers, all of which are home to wild native brook trout. This has negatively impacted Atlantic salmon, and other species as well.

Nonnative muskies, a species more invasive than bass, can now be found throughout the St. John River system, as well as the Allagash River below Allagash Falls. By most accounts, the wild native brook trout in the St. John River and headwater lakes have all but disappeared. Once the muskies get above Allagash Falls, and they unfortunately likely will, the fabled Allagash River and some of the last large lake brook trout populations in the country will be compromised, or worse, lost.

The Penobscot River system hasn’t fared any better with smallmouth bass now found throughout the mainstem, in the West Branch up to at least Nesowadnehunk Falls, throughout the East Branch, as well as in Wassataquoik Stream and Seboeis River up to the first natural barrier. The mainstem Penobscot, East Branch and Wassataquoik are critical habitats for federally, and critically, endangered Atlantic salmon. The presence of bass adds another threat to an already stressed population, and the most important Atlantic salmon population left in the United States.

A more recent ecological disaster is the introduction of smallmouth bass to the fabled Rapid River, the finest wild native brook trout fishery in America. Bass can now be found throughout the river, which puts them on the doorstep of Richardson Lake, and just a short swim away from Upper Dam and Mooselookmeguntic Lake. From there the bass would have access to Cupsuptic Lake, as well as the Cupsuptic and Kennebago rivers. At certain times of year, nonnative bass are now notably more plentiful in the Rapid River than native brook trout.

The wild native landlocked salmon in West Grand Lake and Grand Lake Stream, one of just four native populations, have been displaced by nonnative smallmouth bass. Most of the salmon now caught are stocked, due to the wild fish being unable to compete with the introduced bass. Sebago Lake, the namesake water of landlocked salmon, Salmo solar sebago, Maine’s official State Fish, now has nonnative lake trout, pike, black crappie and largemouth and smallmouth bass.

Two rare Arctic charr waters, Big Reed and Wadleigh ponds, were recently reclaimed to remove nonnative smelt. By the time the Department of Inland Fisheries and Wildlife initiated reclamation efforts on the former, fewer than 15 charr could be found, showing just how close to losing the population we were. Unfortunately, the charr of Bald Mountain Pond to the south won’t be so lucky, as at 1,150 acres, it is likely too big to reclaim. Threatened by both nonnative smelt and lake trout, the population likely will be lost, the first such loss in 100 years.

The list of waters compromised, or lost, to nonnative fish introductions is endless, and includes the entire Belgrade Lakes system which is now home to highly invasive nonnative pike. The ecologically unique, and critically important, Down East Atlantic salmon rivers and streams are now home to nonnative smallmouth bass, and in the case of the fabled Dennys River, apparently largemouth bass as well. At a more personal level, I recently lost my favorite brook trout pond to nonnative golden shiners.

Nonnative fish introductions come in three primary flavors: Deliberate acts of “bucket biology,” accidental release resulting from the use of live fish as bait, and state-sponsored stocking.

In the case of bucket biology, we need to do more to discourage it, like higher fines, higher rewards for turning perpetrators in, and the ability to incarcerate perpetrators for more egregious offenses.

As for live bait, while we have made some headway via region-wide restrictions, due to exemptions, it falls well short of what is needed.

While legal, state-sponsored stocking is a real problem. Consider that from a historic baseline of just four waters, Maine now has over 300 landlocked salmon lakes and ponds, most of which were the result of state-sponsored stocking. The DIF&W is stocking nonnative salmon on top of wild native brook trout in Moosehead Lake, Richardson lakes, Rangeley Lake, Pierce Pond and other waters.

In addition to the ecological impact, what message does this send to would-be illegal stockers when those telling them not to do it are doing it themselves?

To call the proliferation of nonnative fish in Maine an epidemic would be fair. It’s happening because many sportsmen like nonnative fish, and the DIF&W sees stocking as a top priority and important part of their job. And while the non-profits focus primarily on improving habitat, they are failing to address what lives in it, or more appropriately, what shouldn’t live in it. This results in incomplete solutions that address only part of the problem.

Can we save what is left of Maine’s wild native fish? Are we willing to make concessions in regard to what we want to fish for, as opposed to what we should fish for? Are our stewards willing to get dirty and challenge all threats, not just some of them? Native fish are important to Maine, and something that sets us apart from other states. If we want to keep them from going away, nonnative fish will have to become more of a focus than they are today.

Bob Mallard, Outdoors contributor

Bob Mallard has fly fished for 40 years. He is a former owner of Kennebec River Outfitters, a Registered Maine Fishing Guide and a commercial fly designer. Bob is a blogger, writer and author. He is also...