Last week, biologists and fish specialists from the Tennessee Aquarium Conservation Institute (TNACI) and the Tennessee Wildlife Resources Agency (TWRA) had great success during a hunt for dinosaurs in the Tennessee River Basin.
Lake Sturgeon are considered living fossils. A sleek, bewhiskered bottom-dwelling fish, they have remained virtually unchanged since coexisting with the likes of Tyrannosaurus Rex and Triceratops during the Cretaceous Period 65-78 million years ago.
Despite their apparent resilience and timelessness, Lake Sturgeon disappeared from the Tennessee River in the 20th century as a result of over-fishing, pollution and large-river alterations such as dams that impeded their migratory routes to spawning sites.
For more than 16 years, TNACI has been part of collaborative efforts to restore Lake Sturgeon to this part of their native range. In 2000, TNACI initiated a Lake Sturgeon reintroduction project in the Tennessee River. In the last 16 years, its captive propagation program and those run by its partner organizations have stocked the river with more than 190,000 juvenile Lake Sturgeon.
An important step in measuring the program’s success involves a process called sampling — catching and measuring sturgeon from the local watershed — when water temperatures fall below 60 degrees, generally in November or December.
“Sampling directly gives us the clearest understanding of what is actually happening in the environment,” said TNACI reintroduction biologist Clay Raines. “By recording data like length, weight and age and collecting tissue samples, we can estimate population size and genetic diversity, which is the most important thing.”
Raines was part of this year’s sampling effort, which took place the week of Nov. 14th at various locations in the Tennessee River Basin. Three Lake Sturgeon were caught during Raines’ time on Chickamauga Lake near Hiwassee Wildlife Refuge. Prior to 2011, only five Lake Sturgeon had been recaptured by TNACI and other members of the “Saving the Sturgeon” working group.
If the numbers recovered by groups sampling other parts of the watershed are comparable, 2016 could represent the working group’s highest catch year ever, Raines said.
During this year’s sampling effort, TWRA members also pulled in the largest Lake Sturgeon ever recaptured by the working group — a 58-inch, 34-pound monster reintroduced in 2002. That’s a pretty small fry compared to some Lake Sturgeon, which can live up to 150 years and top out at 9 feet long and 275 pounds, but the health of this individual and the apparent abundance of this year’s catch seem to indicate that reintroduction efforts are working, Raines said.
“Fourteen years old is still pretty old for most things in the Southeast,” he said. “These fish are not only surviving but thriving.
“They are perfectly adapted to this new world that was only made possible by the Clean Water Act and proper management of our impounded rivers. Hopefully they will be spawning in the next few years, and then we can call the program a total success.”