Lake sturgeon are native to the Tennessee and Cumberland rivers but largely disappeared from Tennessee waterways by the 1960s. Thanks to the Tennessee Wildlife Resources Agency, the Tennessee Aquarium, and other Lake Sturgeon Working Group member organizations, the fossil fish are making a comeback.
These groups have been restoring sturgeon for 20 years. Despite their efforts, all the lake sturgeon in the Tennessee River are introduced fish. No spawning has been recorded. Male sturgeon reach reproductive maturity from 15- to 20-years-old. Females reach maturity sometime after their 20th year. Until the late 20th century, lake sturgeon were a successful commercial fishery in Tennessee coveted for their roe.
Thom Benson of the Tennessee Aquarium compared the ongoing sturgeon effort to a similar brook trout reintroduction program. The trout were regularly spawning and populating the rivers where they were released after five years. He hopes for a similar level of success with the lake sturgeon program.
Wildlife managers use the term ”recruitment“ to describe the process of new individuals joining a wildlife population. Organizations involved in sturgeon recovery are now monitoring the rivers, looking for signs of natural recruitment. They hope to be able to stop the release of captive-reared individuals and rely on the sturgeons’ own ability to reproduce.
The Tennessee Wildlife Resources Agency hopes to open a sturgeon fishery eventually, but for now it is illegal to harvest sturgeon. TWRA asks any angler who happens to catch a sturgeon to measure, photograph, and quickly release the fish and send in a picture. The angler will receive a certificate.
Benson refers to the sturgeon as an indicator species that reveals the river’s health. They disappeared due to habitat loss and fragmentation and overharvesting. The habitat fragmentation obstacle was overcome by redesigning dams so that sturgeon could migrate up and down the river.
The sturgeon released on April 22 were yearlings, raised from eggs and semen collected in Wisconsin, where a healthy population of lake sturgeon still thrives. As the release took place, aquarium staff members were in Wisconsin collecting eggs and semen to produce fish for next year’s release.
The fish can reach 9 feet and weigh in at 90 pounds. Some have lived as long as 150 years, but these are outliers. Sturgeon are, nevertheless, long-lived species.
The lake sturgeon is the only species found in the Tennessee River. Pallid sturgeon and shovel-nosed sturgeon are found in the Mississippi River. There are 27 sturgeon species worldwide, of which four may be extinct.
The lake sturgeon is recognized as endangered by the state of Tennessee but does not appear on the U.S. Fish and Wildlife Service endangered species list. The Courts have ordered the US Fish and Wildlife Service to make a legal determination regarding this fish by 2024. The International Union for the Conservation of Nature lists sturgeon as the most endangered group of animals worldwide.
At least one group is making a last stand in the Tennessee River.
Correction: This article has been updated to clarify that commercial sturgeon fishing on the Tennessee River ended in the 20th century.