Lake Sturgeon Make a Comeback
This ancient fish, once extinct in the Tennessee River system, has made a comeback thanks to a savvy reintroduction initiative by TVA and its partners.
The lake sturgeon (Acipenser fulvescens) isn’t a handsome fish. It looks like what it is: primeval. Evolutionarily ancient, its body is comprised of bony plates, giving it a lumpy, bumpy appearance. As a bottom feeder, it sports a pointy nose with odd rubbery lips. And it can be both huge (growing up to six feet long and weighing upwards of 200 pounds) and old (living 60 years or more).
“They’re nothing you’d want to cuddle up to,” says TVA aquatic zoologist David C. Matthews. Still, he’s always glad to see them. “They’re a big, long-lived fish that’s a natural part of our eco-system. It’s a good thing that they’re here.”
That wasn’t always the case. Native to the Tennessee Valley, lake sturgeon became extinct in the region during the 1960s, partly due to overharvesting—the females were prized for their eggs, a.k.a. caviar.
“It’s a species that takes a long time to come to maturity for 10 or 12 years, and that doesn’t reproduce every year,” Matthews explains. “Overharvesting really affected them.”
TVA dams exacerbated the problem. “The river fragmentation at the time didn’t help,” he says. This interrupted the lake sturgeon’s natural migration patterns.
“There were a lot of reasons they declined and, unfortunately, disappeared.”
Change for the Better
In the 1990s, however, TVA began to change the way it operated its dams, coordinating releases so that the river acted more like a river rather than just focusing on each dam in isolation, according to Matthews.
Also, it undertook an initiative to improve oxygen content in the tailwaters. “When we draw water down now, it’s not that bad, low-oxygen water it used to be,” Matthews explained. “We really looked to improving aquatic life downstream.”
Conditions were right for a reintroduction of the species. So TVA joined forces with partners such as the U.S. Fish and Wildlife Service, the Tennessee Wildlife Resources Agency, the Tennessee Aquarium, Tennessee Tech and other partners to bring back the lake sturgeon.
In the early 2000s, the partners began to restock the river—a massive effort that to date has seen 170,000 juvenile lake sturgeon set free in the Tennessee River, and an additional 23,000 in its tributary, the Cumberland River.
One of the most visible parts of the effort is Sturgeon Fest, an autumn event that each year invites Knox County school children to release lake sturgeon into the French Broad River (another Tennessee River tributary) at Seven Islands State Birding Park. Each fish is 4 to 6 inches in length—the size thought to be optimal for survival.
“It really is a big success,” says Aurora Pulliam, the TVA recreation representative who helps organize the event. “The U.S. Fish and Wildlife Service brings the fish, and the kids will get them in hand and carry them to the water. There are all these aquatic and fisheries biologists standing around, and they are very approachable and will talk to the kids about anything. We see it as an opportunity to talk to the next generation of lifelong conservationists.”
That’s important, as it will take many more years to ensure that the lake sturgeon population is well established, and that the project is a successful one. So far, it looks good, says Matthews.
“We are starting to monitor now using baited trout lines,” Matthews explains. “We come in, collect them, weigh and measure them and put tags in them so that we know if we recapture the same fish again.
“So far, we’re not seeing a lot of tagged fish, so that tells us that there are a lot of them out there. And we’re seeing a lot of age structure—different sized fish—and that tells us they’re doing just fine. We had one a couple of weeks ago that was 50-inches long!”
It’s early yet, in the grand scheme of things, but hopes are high that a river-wide reintroduction will be successful. “This is a top-rated conservation initiative in the country right now, just because of the scope of it,” Matthews explains. “It’s one thing to reintroduce a fish on a creek level. We are stocking an entire river system. We’re seeing them from Knoxville to Guntersville. “
The lake sturgeon is a protected species; if you catch one, set it free. Then call the Tennessee Wildlife Resources Agency and let them know where and when you caught it. “We use that data,” Matthew explains. “They’ll even send you a little certificate that says you caught a lake sturgeon.”
You’ll have played your part in a very good thing. “From the 60,000-foot view, its amazing that with a little money and effort, we can bring a species back to its former home,” Matthews concludes. “It just takes a little help from man.”