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April 1 used to mark the opening of the Atlantic salmon fishing season on the Penobscot River in Maine. Anglers in pea pods would vie for the honor of catching the first fish, and commercial salmon fishermen would set their weirs, nets, and traps into the snowmelt-swollen current.
But as the species declined, from tens of thousands of fish in the 19th century to a few thousand in the early 20th, people became disconnected from the so-called king of fish. Commercial fishing ended in 1947; salmon angling became catch and release only in the 1990s; and all fishing ceased in 1999, when the Atlantic salmon was placed on the US endangered species list.
Throughout all of this time, hatcheries supported the population. Salmon aquaculture on the Penobscot River originated in 1871, and kept the species alive through decades of pollution and dam construction. But the population continued to dwindle. In 2020, an estimated 1,439 Atlantic salmon returned to the Penobscot River, and 26 returned to the Machias River, 130 kilometers east. It was a “good year”—but a fraction of historical numbers, and nearly all originated in a hatchery.
In the first major change in salmon management in half a century, state and federal fisheries agencies, in partnership with the Penobscot Nation, are about to begin a new experiment—one that is expected to succeed where others have failed, and hopefully bring wild salmon back to these rivers.
“We’ve tried so many things, stocked every life stage, done so much restoration with nothing to show for it. The fish are basically on life support,” says Dan McCaw, a fisheries biologist for the Penobscot Nation. “Maybe with climate change we just can’t do it. But we have to try.”
Led by Sean Ledwin, the director of the Sea Run Fisheries and Habitat Division at the Maine Department of Marine Resources (MDMR), the experiment departs from Maine’s conventional salmon restoration efforts, which involved putting salmon into rivers as smolts that would promptly swim out to sea. Upon their return as adults, they were trapped and trucked to the hatchery for spawning—and the cycle repeated. “Hatcheries have kept the species alive, but not resulted in any significant increase in fish,” says Ledwin.
Everyone involved seems to agree that, ideally, young salmon should be hatched in the wild rivers where they evolved. Fish that are born in the wild are more robust and more likely to survive their journey to sea and back than those reared in a hatchery, Ledwin says. But there aren’t enough adult wild fish around in Maine to repopulate the rivers naturally.
So, state, federal, and tribal partners are trying a new approach.
This spring, the US Fish and Wildlife Service will transfer roughly two-year-old smolts from their hatchery to open-net pens off the coast. There, aquaculture giant Cooke Aquaculture, a company that operates commercial salmon farms in Maine and around the world, will tend the fish, feeding them and keeping predators like seals away for another 18 to 24 months.
Then, if everything goes according to plan, thousands of adult salmon will be transferred to the East Branch Penobscot and Machias Rivers. There they will select their own mates, find places to spawn, and lay eggs in the gravel—giving rise to a whole new generation of wild-born fish.
That the project is relying on hatchery-raised fish isn’t ideal, says Emily Bastian of the Native Fish Coalition, a nonprofit organization focused on protecting and restoring wild fish. “We recognize the need for hatchery involvement at this point, but the faster we get the fish out of the hatchery the better off we are,” she says.
MDMR agrees, and may use wild juveniles from each river to stock the net pens in future years if the project is successful. But for now it’s all about the numbers, putting enough salmon in the river to jump-start an increasing wild population, says Ledwin.
Unlike in other places, where an influx of hatchery-raised fish can put pressure on, and dilute the genetic diversity of, remaining wild stocks, the Penobscot and Machias Rivers have few purely wild fish to protect. Their best chance of restoring wild self-sustaining runs in Maine, Ledwin says, is to go big. They need thousands of adults to spawn in the wild. Hatcheries don’t have room for that many adults, which is why they are raising the salmon in Cooke’s open-net pens.
Dwayne Shaw, of Downeast Salmon Federation, a nonprofit organization that promotes fish conservation in eastern Maine rivers, says that it may seem crazy for salmon conservationists to work with the aquaculture industry because of the impact salmon farms can have on wild populations, including genetic pollution from escaped fish. But he says it’s necessary. “Without these interventions, Atlantic salmon are doomed.”
A similar but smaller-scale effort that has been ongoing in Fundy National Park, New Brunswick, since 2009 is credited with a measurable increase in returning salmon, says John Whitelaw, a Parks Canada ecologist. After raising salmon to the adult stage in open-net pens and allowing them to spawn in the wild, a 2020 count of 38 salmon in two rivers was one of the best returns in the last decade, and far better than the total of zero to eight fish counted in the years prior to 2009. “Evidence is mounting that Atlantic salmon have a better chance of survival if their time in captivity is limited,” says Whitelaw.
The fish that eventually will be born and raised in these two Maine rivers should have an advantage over the hatchery-raised juveniles the state has been releasing for more than a century. However, they will still face challenges.
The Gulf of Maine is among the fastest-warming parts of the global ocean. Scientists blame changing ocean conditions for declining salmon populations across the North Atlantic. Also, though two dams were recently removed on the lower Penobscot River, fish migrating to and from the East Branch still have to pass over three dams. “We have to be realistic about passage issues,” says Dan Kircheis, the Penobscot Bay salmon recovery coordinator with the National Marine Fisheries Service.
McCaw hopes the thousands of salmon in the East Branch Penobscot River will be an opportunity for tribal members to connect with a part of their heritage that has been absent for hundreds of years.
Most people living in Maine today have no experience with a river full of fish that once sustained the Penobscot and Passamaquoddy peoples, supplied the colonial enterprise, and supported an annual tradition of delivering the first salmon caught each season to the president of the United States.
Someday soon, on the East Branch Penobscot and Machias Rivers, people will once again have a chance to know salmon, and salmon—ocean-raised and wild-spawned—will once again have a chance to survive.