Stacy Furgal woke up early to meet the truck at the stocking barge. She wanted to be there in person when the lake trout from the Dwight D. Eisenhower National Fish Hatchery in Chittenden, Vt., were piped into Lake Ontario. Two weeks prior, she spent the day in Vermont, helping a research team lead by Alexander Gatch of the U.S. Fish and Wildlife Service, perform surgery on 38 very special fish – implanting tiny devices that will register data points on an array of underwater acoustic receivers. A total of 77,000 lake trout were released at that location on that day in 2017.
The data, now documented in the Journal of Great Lakes Research, is helping scientists understand the behavior of stocked lake trout.
At one point, lake trout were abundant in the Great Lakes – a beloved cultural staple of Lake Ontario as well as an economic asset. But commercial harvesting, overfishing, sea lamprey predation and habitat degradation have all contributed to expatriation. Lake trout introduced through stocking programs haven’t been able to reproduce at a scale to sustain their own population though, and researchers don’t yet know why.
While lake trout aren’t harvested commercially anymore, there’s still a recreational industry around fishing the Great Lakes. “Lake trout are a native species,” said Furgal. “There’s a big push to restore them for that reason, for the cultural and historic significance. There's a lot of funding and enthusiasm by new and old world researchers to go all in and figure out why stocking programs aren’t working, she added. “We wanted to look at these hatchery raised fish right as they were going into the lake to see what kind of mortality they were incurring at that stage.”
Previous research would have relied on bottom trawl or gillnet collected information. “This only gives you data from one moment in time,” said Furgal. “With the acoustic telemetry we’re using, we get millions of data points from all our tagged fish. As long as we have a receiver listening, we get a much better picture of where they're going.”
Furgal’s research team was the first to use acoustic telemetry to monitor lake trout at this life stage. The information will be used to better understand how juvenile lake trout move through the lake.
“We had gone in with the assumption that temperature was going to be a main driving factor,” she said. “But when our study site had its first warm water incursion, most of our tagged fish had already left. That tells us that something else is at play.”
What that x-factor is, food availability, predators, or something else that caused the fish to leave is still unknown, but the research provides an important starting point for further studies.
“Lake trout have previously been distributed equitably within the various regions that the shore is divvied up into. But now managers are evaluating stocking locations more closely, considering the factors that might increase survival. Understanding what conditions are best for stocked lake trout survival will also help us while we’re figuring out the limitations for natural reproduction.”
The research was highlighted over the summer by the Women in Fisheries organization, a networking group for women in fish science. “The network there exists because this is a field that has traditionally been cis white male,” Furgal said. “But it is becoming increasingly more diverse. I've been lucky in my career that I've had all sorts of different mentors, and accessing a group like that has been really helpful, and creates networks that are important for retaining diversity in the field”
Furgal grew up in Williamstown in Oswego County, and was inspired to go into science after meeting a fish biologist in high school. “I think this is a career path that doesn’t come to mind even when you’re considering something like biology,” she said.
Her role as a Great Lakes Fisheries and Ecosystem Health Specialist is to communicate research and best practices to Great Lakes communities, stakeholders, and resource managers. She is part of New York Sea Grant, a collaborative program between Cornell and the State University of New York.
Said Furgal: “It's a really exciting time to be working in the lake right now. There's this great collaborative mindset. People from all different, even outside disciplines, we're working with geologists, modelers, trying to address these questions. And my role as an extension specialist is to take this information and convey it to new and existing audiences and provide opportunities to directly engage with the science.”
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