After a summer spent growing big and strong on a diet of bloodworms, the latest class of Lake Sturgeon finally graduated on Saturday, from the Tennessee Aquarium Conservation Institute. Their release into the Tennessee River further swells the ranks of more than 179,000 Lake Sturgeon that have been reintroduced to the Tennessee River since 2000.
This weekend, representatives from the Tennessee Aquarium Conservation Institute traveled to Kingston, Tennessee, where they gently slipped 1,000 juvenile Lake Sturgeon into the Clinch River during John Muir Fest, an even named for the self-same conservationist credited as “the Father of the National Parks.” The 337-mile Clinch River flows southwest from Tazewell, Virginia, to Kingston, where it joins the Tennessee River.
This release marked the first for this location.
Previously, juvenile Lake Sturgeon raised at the Aquarium have been released in the French Broad River just before it joins the Holston River to form the Tennessee. The new location was chosen based on a study by Todd Amacker — a graduate student at the University of Tennessee at Knoxville — who found that Lake Sturgeon in the Watts Bar Reservoir were healthier due to access to a more plentiful food supply.
“Prey availability is much, much higher and much better quality in Watts Bar,” said Tennessee Aquarium Conservation Institute Reintroduction Biologist Meredith Harris. “You can tell, when you pull the fish out of there; they’re big and healthy — fat and happy.”
This year, the Aquarium also took additional steps to accurately track the Lake Sturgeons’ movement throughout the river system. Coded wire tags measuring a couple of millimeters in length were inserted into the rostrum (snout) of the Lake Sturgeon. During future sampling efforts, researchers will be able to use a wand-like device to detect the presence or absence of tags in collected fish to determine their initial release location.
“That will help us determine if they’re able to move upstream through dams as well as downstream,” Ms. Harris said. “That’s an important factor in determining if this is going to be a successful conservation program. If the fish can’t navigate the locks — if they remain isolated from each other because of these dams — then that’s going to cause some problems.”
This year marks the 20th anniversary of the formation of the Tennessee Lake Sturgeon Working Group, which was founded by a group of scientists, including those at the Tennessee Aquarium Conservation Institute (then called the Southeast Aquatic Research Institute). The Working Group’s inception in 1998 was an attempt to right an ecological wrong by bringing the Lake Sturgeon back to its native waters.
By the 1970s, Lake Sturgeon had all but disappeared from the Tennessee River due to overfishing, low water quality and the disruption of the waterway through damming, says Dr. Bernie Kuhajda, the Aquarium’s manager of science programs.
“Lake Sturgeon are an important part of large river ecosystems,” Dr. Kuhajda said. “Having one of those large predators missing from the river system disrupts the natural balance.”
By the 1990s, legislative measures such as the Clean Water Act of 1972, protection of Lake Sturgeon as a state-endangered species and dam improvements implemented by TVA had improved conditions in the Tennessee. The Lake Sturgeon Working Group coalesced because its founders determined that, with a little help from conservationists, the river could once more support a self-sustaining Lake Sturgeon population.
“The project reaching this age really shows commitment with funds and expertise and energy and interest from all of the partners that are required to make this work,” Dr. Kuhajda said. “Over the last 20 years, this process has involved literally hundreds of people. For something this big to go on for so long, you have to have people who think this is a pretty cool and worthwhile thing to do.”
At its inception, the Lake Sturgeon restoration effort was solely focused on the Tennessee River. Since the Working Group’s formation, organizations in other states have joined the effort, which now encompasses even more of the species’ historic range, including the Coosa River system in Georgia and Alabama, the Cumberland River in Tennessee and Kentucky and the French Broad River in North Carolina.
Despite nearly two decades of annual releases, however, the overall success of the program has yet to be determined. Lake Sturgeon have been recorded living for more than 150 years, and as is typical for long-lived species, they don’t reach sexual maturity until late in life (15 years for males and 20-33 years for females). As a result, scientists won’t know if the propagated Lake Sturgeon have started successfully breeding for at least two more years, when the earliest re-introduced females may achieve sexual maturity.
When the first signs of spawning are found, however, it will be a monumental payoff for decades of hard work and perseverance.
“That’ll be really exciting,” Dr. Kuhajda said. “It’ll sort of be completing this big, wonderful, long-term picture that the folks back in the late ’90s envisioned when they established the Lake Sturgeon Working Group.”
Members of the Tennessee Lake Sturgeon Working Group include:
· U.S. Fish and Wildlife Service
· Tennessee Wildlife Resources Agency
· Tennessee Valley Authority
· U.S. Geological Survey
· The Tennessee Aquarium
· Tennessee Technological University
· University of Tennessee at Knoxville
· Conservation Fisheries Inc.
· The Tennessee Clean Water Network
· Wisconsin Department of Natural Resources
· World Wildlife Fund.