Native lake trout success story in Lake Champlain: stocking to end this year

As wild population thrives, New York, Vermont and feds celebrate milestone in decades-long restoration work

By Zachary Matson

The long-running effort to restore lake trout to Lake Champlain reached a momentous milestone last week as officials from New York, Vermont and the federal government agreed to suspend the stocking of hatchery-raised trout after this spring.

The native fish has been restored to the nation’s 13th largest lake, officials declared.

“It’s kind of dismaying how rarely we get to declare ‘job done,’ because often there are things we can’t overcome like habitat damage or invasive species,” Ellen Marsden, a University of Vermont fisheries scientist and the region’s leading lake trout expert, said Tuesday. “This is one of those quite rare events. It was rapid and obviously successful.”

The decision to end stocking comes as a growing population of lake-born wild trout have convinced scientists and fisheries managers that the lake’s top predator species can sustain itself without the help of human-reared fingerlings. After decades of stocking, paired with work to kill sea lamprey that harm lake trout, the joint effort started to pay dividends about 15 years ago.

RELATED READING: From stocking to self-sustaining? The return of Lake Champlain’s trout

Scientists and lake managers knew for decades that stocked fish were surviving, growing, spawning and hatching fry. Anglers enjoyed a healthy lake trout fishery—all those fish with clipped fins, science’s way of identifying fish raised in hatcheries.

Since sustained stocking started in 1973, though, there was no evidence wild fish survived their first winter. That is until 2012.

Marsden and colleagues in 2015 found young unclipped lake trout cruising the 400-foot-deep lake—the oldest in their third year. 

Watch: A conversation between Adirondack Explorer water reporter Zachary Matson and University of Vermont researcher Ellen Marsden about the successful rebound of wild lake trout in Lake Champlain. The talk took place Sept. 25 over Zoom.

After five more years of sustained wild fish survival, a cooperative of the New York Department of Environmental Conservation (DEC), Vermont Fish and Wildlife and U.S. Fish and Wildlife Service cheered the growing wild population and agreed to cut stocking levels. They reduced stocking again last year to 41,000, about 25% of historic levels. 

The rare conservation success, though, left fisheries managers puzzling over when to hand the fishery over to the fish. Experts agreed they should eventually stop stocking and let the emerging lake trout population sustain itself. But it was a complicated calculus.

Researchers don’t know what enabled wild fish to flourish, so it’s hard to know what to protect against. Lake trout can live more than 30 years, so trends are slow to show in data, and the effects of the latest stocking reductions were still working through the population. There’s no playbook since few lake trout restorations anywhere have yielded a wild population.

“It’s a new and exciting situation for us to be in,” Rob Fiorentino, DEC Region 5 fisheries supervisor, said in an interview last year. “There’s nothing really written for us to work off.”

During its annual meeting last week, the lake management cooperative decided it was time to end stocking after the batch raised to be released this spring are dropped into the lake. The cooperative will continue to monitor the trout population and develop benchmarks for reinstating a stocking program if the population waivers. Marsden said it will be critical to monitor the populations of the other fish species trout feed on as well as ensuring young fish are aging into maturity. Mortality is highest in the first year of life.

“This restoration effort serves as a model for states to effectuate positive and collaborative conservation outcomes,” DEC acting Commissioner Amanda Lefton said in a statement.

Photo at top: Dan DeLucia, a seasonal employee with the Vermont Fish and Wildlife Department holding a lake trout caught during a summer survey. Photo by Zachary Matson