Wildlife Watch: Biologists aim to improve trout health
BURLINGTON, Vt. (WCAX) - Every year, hundreds of trout are raised in fish hatcheries and then released into Vermont waterways, including Lake Champlain. But this year, state biologists are taking a different approach when it comes to the broodstock they are gathering.
Our Ike Bendavid spoke with Vermont Fish & Wildlife’s Shawn Good about efforts to improve trout health and resiliency for future generations.
On the shores of Lake Champlain near the Grand Isle ferry, crews are working an assembly line measuring, weighing and then passing off fish into a truck to bring them into the hatchery.
“We are just getting a snapshot of their size distribution,” said Shawn Good, a Vermont fisheries biologist.
This happens every year to check on the health of the fish, but this year crews are working hard to create a better trout population in the future.
“This year we are doing something a little different,” Good said.
With some warm weather in early November, we join the crews of biologists from Vermont and U.S. Fish and Wildlife and the University of Vermont on a boat in the bay as they pick up their next round of fish. This is the time of year they arrive on the shoreline to spawn. Crews set a net overnight.
“All the fish are kept alive,” Good said. “It’s a passive fishing technique. The fish kind of catch themselves in that box as they mill around overnight.”
Good says the goal of today is to take trout that have survived in the lake and use their eggs and milt to use at the hatchery to reproduce trout for the future. It’s something they have been doing with salmon for years.
“Normally we raise these fish from broodstock-- cap to broodstock that we keep at one of our hatcheries but these are feral fish that have been stocked and have now lived for multiple years in the lake and, in a sense, have sort of proven themselves to be genetically superior or able to actually survive lamprey predation, grow to good sizes, feed well and return to spawn themselves this year for the first time. We are really trying to make an effort to take eggs from those fish that have basically proven themselves out in the lake as being superior survivors and we are going to take those eggs from these fish, 35 males and 35 females will go to the hatchery and bring on the next generation of lake trout,” Good said.
Back on the shore, crews continue to log data on the fish that includes sea lamprey information that biologists say has been improving.
“We are also collecting wounding data from them, so we are counting how many sea lamprey holes they have in their bodies which is giving us an indication on how well we are doing with our sea lamprey control program. What we want to see over time is fewer and fewer wounds on the sides of these lake trout,” Good said.
But the goal is that these fish caught today will be the start of a stronger and larger population in the future.
“Over the course of time, even though we rotate our captive broodstock out and refresh them in the hatchery, they do have the potential to have some genetic implications of keeping them and taking eggs from them, the same fish year after year. Whereas these fish are out, they are in the lake, they are mixing, there are multiple year classes, they are facing all the pressures that go on out in the lake whether it’s angling mortality or anglers catching them and keeping them or sea lamprey mortality or just general environmental conditions that result in some fish not surviving, but the ones that do survive, it’s like the hunger games. They have run the gamut. They have proven themselves as survivors and here we are, we are going to take their eggs and milt and grow them in the hatchery for stocking back out in the lake,” Good said.
As anglers wait to see the progress down the line, ones I talked with say they appreciate the work for a healthy trout population
“I think they have done a good job managing the fishery so far,” said George Taft of Colchester.
“I think the Vermont Fish and Game does a great job,” said Jim Reiman of Barnard.
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