At a Vermont Fish and Wildlife sampling station in South Hero, a tiny brook is alive with splashing dorsal fins. It's full of landlocked Atlantic salmon from Lake Champlain fighting their way upstream to spawn. This year, the fish are arriving in record numbers.
“We’re definitely seeing more salmon coming back, here and in other rivers,” says Brian Chipman, a fisheries biologist with Vermont Fish and Wildlife.
“We’re monitoring the Lamoille River, the Missisquoi River, Otter Creek, as well as the Winooski — and in just about all of them, we’re collecting more salmon in those rivers so far this fall than have in long, long time.”
Here at a small brook by the Ed Weed Fish hatchery on Grand Isle, Chipman and other biologists are catching the spawning salmon to gather data, and to harvest eggs for the hatchery.
Last year the department constructed a sort of one-way gate to trap the fish, so they could sample the salmon without delivering electric shocks to the water. Chipman says this trap saw 700 fish last year, and this year they’ve already handled 1,000 unique fish and counting at just this brook.
Chipman weighs the fish, measures their length, and puts a tag on each for tracking if the fish is caught again. He also scrapes off a few scales to study back at the lab.
“We can age them back in the lab, under magnification. They put down rings, similar to tree rings to determine their growth,” says Chipman.
Chipman says most of the returning salmon spend a year or two in the lake before returning to spawn.
As he’s tagging the fish, he’s also checking their bellies to look for existing markers that tell him where the fish came from. Different hatcheries will clip a right or left underbelly fin to mark the fish, and Chipman wants to have a diverse mix of source, size and age for this hatchery’s eggs.
Fish that make the cut for the hatchery get tossed into one container, and the rest of the spawning salmon will be re-released into the lake a few miles down the road.
“The landlocked salmon that were in Lake Champlain are extinct, they pretty much disappeared in the 1800s,” says Chipman.
“But we have stocked salmon a strain from Sebago Lake, Maine, which has performed well in Lake Champlain, and these are progeny of those stock," he adds.
And while their ancestors may be from Maine, these fish remember their birthplace in the hatchery. Chipman says many of the fish he’s sampling are those born and released in this very brook.