What do you do when you realize that one of your state’s most beloved fish is at low population levels?
You build them an elevator, of course.
In Wisconsin, sturgeon are a revered fish species. Throwbacks to the age of dinosaurs, the fish are prehistoric in age and appearance. They’ve been around a long time.
Indigenous tribes like the Menominee, Winnebago, Ojibwa, Potawatomi, Oneida and Sauk tribes all revered the giant fish, which can get up to 16 feet long and weigh up to 800 pounds. But when European settlers who moved into the territory in the 1800s considered the fish a nuisance.
“They viewed lake sturgeon as a fish that caused problems for them – it got into their gear and tore up their nets,” Fred Binkowski, a University of Wisconsin-Milwaukee Senior Scientist with the Great Lakes Water Institute, told the Wisconsin Department of Fish and Wildlife.
In 1865, settlers started to see the value of lake sturgeon. Whether for their flesh or their eggs, they were a prime food source. Other parts of the fish could be used to make products like oil, glue, and leather. Some settlers even used gelatin extracted from the fish’s swim bladder to make jams and jellies and to clarify alcoholic beverages.
But in recent decades the sturgeon population was down to about 1 to 2% of its historic abundance, according to Patrick Forsythe, a professor of biology at the University of Wisconsin Green Bay,.
Some of the decline was due to overfishing, he said, but most was due to a dam system. Built in the early 1900s, the five dams along the Menominee River were first put in to help logging operations along the river. As time passed, the dams were converted to hydro-electric dams to help fuel the area with electricity.
That presented a problem for sturgeon, he said.
Like salmon, sturgeon have to swim back and forth to their spawning grounds. The rocky river bed of this particular spawning ground, Sturgeon Falls in Wisconsin, gives the eggs the right environment they need and gives young sturgeon the protection they require to grow stronger. Unlike salmon, however, sturgeon aren’t really all that athletic, so there’s not as much jumping up waterfalls like you’d see salmon doing.
The dams prevented them from swimming back and forth between Sturgeon Falls and Lake Michigan. That resulted in a drop in the population, and the community took notice. Through a cooperative effort of federal, state, and local government agencies, electric companies, and others, fish passage was built, complete with a fish elevator, to help transport the fish back and forth.
On the upstream trip, fish swim into a holding area which then acts like an elevator and raises them up to the land. There, researchers check their health, do an ultrasound, and take a small DNA sample from their fins. Then, they’re put into the back of a truck and driven upstream.
For the downstream trip, authorities built a fish slide that helps them quickly navigate from Sturgeon Falls to Lake Michigan.
It’s Forsythe’s job now, thanks to a $300,000 grant from the Great Lakes Fish and Wildlife Restoration Act and WE Energies Mitigation and Enhancement Fund, to research whether or not the fish elevator is working.
Knowing whether the fish are migrating back and forth is important, Forsythe said, not only for the fish’s health but to see whether the efforts to bring the big fish back have been successful.
“Within the last three to four years they’ve really been making an effort to pass quite a few fish on an annual basis,” he said. “The first step was to figure out if those fish would just fall right back down through the dams or would they go upstream. And some fish do just come back through the dams after they’ve been transported, but a large proportion of them were going upstream.”
Forsythe and his team will be using the DNA samples to determine whether the young fish at Sturgeon Falls are the product of two fish who stayed in the river, two fish who moved through the fish passage, or a fish that stayed in the river that mated with a fish that went through the passage.
The project is important to see whether the program is working and to determine how to manage the fish passage in the future. It’s also important for the people of Wisconsin, he said.
“You know, the sturgeon are highly revered in the Great Lakes. They call them the King of the Fish,” Forsythe said. “Tribes used to sustain themselves based on the surgeon harvest. Actually, Indian tribes locally, they probably knew more about sturgeon than what we do because their migratory behavior was tied to the sturgeon migrations as well.”
According to a 2009 study, increasing sturgeon population levels by just 10% could provide more than $2 million in tourism revenue just for fish viewing.
Once the initial DNA testing is done, Forsythe said, researchers will use that data to look deeper into the fish population. The data will tell them which adult fish were most successful at spawning and what characteristics they had. That information can be used by wildlife management, Forsythe said, so they can plan on how many fish need to pass through the passage each year, and which fish would have a better chance at successful spawning.
For Forsythe though, it’s a chance to bring back a fish he’s loved since childhood.
“I think they just got hammered by overexploitation and river pollution. They’ve seen a resurgence recently, and I think people just want to see that and see them come back,” he said. “You know this is just a really cool prehistoric animal.”