Biologists with the Tennessee Aquarium on Wednesday evening brought 2,500 baby lake sturgeon to their conservation institute, where the fish will be monitored, fed and raised until the fall, when a collection of agencies will release them into the Tennessee River system.
The effort is part of a reintroduction program that began 20 years ago to propagate the fish population. Lake sturgeon, the largest fish in the Tennessee River system, had disappeared in the 1970s because of poor water quality, excess commercial fishing and a lack of environmental controls when Tennessee Valley Authority built the river's dam system. Representatives from the aquarium, Tennessee Wildlife Resources Agency, Tennessee Valley Authority and University of Tennessee have been working since to repopulate the Tennessee River with the fish.
"The more fish you lose, the more the river system becomes unhealthy," aquarium aquatic conservation biologist Bernie Kuhajda said. "We lost a pretty big part of that ecosystem when they disappeared. We feel this helps rebuild one of the building blocks of the system. Plus, it's a really cool fish."
Lake sturgeon are one of the oldest known species to swim in the Tennessee River. The sturgeon at the research institute currently measure less than a few centimeters but grow quickly. They will be several feet long when they are released this fall and can grow up to 8 feet in length. The prehistoric fish are also featured in the aquarium's "Monster Fish" exhibit and are displayed in a tank that allows guests to touch them.
As far as their role in the ecosystem, TWRA biologists aren't entirely sure of the full benefits the fish provide, assistant chief of fisheries Jason Henegar said. However, they are bottom feeders, he noted, which provide a healthy river system and clean water used by humans, Kuhajda said.
The first two years of the program leading up to the initial release in 2000 were spent planning and raising the fish. Since 2000, the groups have released more than 180,000 into the Tennessee River and more than 220,000 total.
"It's important to re-establish this native species into the state to help manage our aquatic ecosystem as a whole," Henegar said.
The program wants the sturgeon population to reach a point where it is self sustainable and can repopulate on its own. They believe that will take about five more years. The 25-year effort will give the population enough genetic diversity to allow it to be be self-sufficient and not have problems associated with inbreeding.
However, even after the repopulation is completed, biologists will continue to monitor the fish. To do that, they are counting on fishermen.
It is illegal to catch and keep lake sturgeon, but anglers are encouraged to catch, document and release the fish. Anglers who catch lake sturgeon are asked to notify state agencies about the size of the fish and where they caught it by calling 615-781-6575 or emailing email@example.com. Officials also ask for a picture if one can be taken without harming the fish. Anglers who report their catches receive a certificate. Since 2006, more than 400 anglers have reported catching the fish.
"Getting fishermen involved is important," Tennessee Aquarium spokesman Thom Benson said. "It really helps scientists monitor the population."