Sturgeon are among the most ancient fish species on Earth, characterized by rows of bony plates, called scutes, instead of scales. These bottom-dwelling fish can grow to immense sizes and use four barbels, or whiskers, near their sucker-like mouths to sense for food on the river bottom. Sturgeon are present in Tennessee today, largely due to extensive conservation efforts. Populations that once thrived in the state’s major river systems were nearly lost, but a multi-agency restoration program is now working toward re-establishing a self-sustaining population.
Sturgeon Species Native to Tennessee Waters
Three species of sturgeon are native to Tennessee’s waters, primarily within the Mississippi, Cumberland, and Tennessee River watersheds. The species central to restoration efforts is the Lake Sturgeon (Acipenser fulvescens), Tennessee’s largest and longest-living fish. Lake Sturgeon are dark, robust fish that can grow to eight feet in length and weigh up to 300 pounds, with females living up to 150 years. They are typically found in the deepest parts of large rivers and lakes, using their barbels to locate small prey like mollusks, insect larvae, and crayfish.
The other two native sturgeon species belong to the genus Scaphirhynchus: the Shovelnose Sturgeon (Scaphirhynchus platorynchus) and the endangered Pallid Sturgeon (Scaphirhynchus albus). The Shovelnose Sturgeon seldom exceeds 30 inches or six pounds and is common in the main channel of the Mississippi River, preferring moderate to strong currents. They are bottom feeders that mainly consume aquatic insect larvae. The Pallid Sturgeon is very similar in appearance to the Shovelnose but is one of the rarest fish in Tennessee, found almost exclusively in the Mississippi River, and is federally protected.
The History of Decline and Extirpation
The collapse of sturgeon populations in Tennessee began in the late 19th and early 20th centuries due to intense commercial exploitation. Lake Sturgeon eggs were highly prized for the caviar industry, leading to unsustainable harvesting practices that decimated the slow-reproducing species. This fish is vulnerable to overfishing because females take 20 to 33 years to reach sexual maturity and only spawn intermittently, typically every four years.
The construction of major hydroelectric dams by the Tennessee Valley Authority (TVA) throughout the 1900s exacerbated the decline by altering and fragmenting the river habitat. These dams blocked the sturgeon’s long-distance spawning migrations, preventing them from reaching upstream rocky substrate areas to reproduce. Fluctuating river flows, water pollution from industrial sources, and habitat degradation during the mid-20th century further contributed to the decline. By the 1950s and 1960s, the Lake Sturgeon was considered extirpated from the Tennessee River system, with the last documented sighting prior to restoration occurring in the 1970s.
Current Restoration and Protected Status
Current sturgeon conservation is a multi-agency effort focused on restoring the Lake Sturgeon to the Tennessee and Cumberland River systems. The goal of this long-term project is to re-establish a naturally reproducing, self-sustaining population. Since 2000, a partnership including the Tennessee Wildlife Resources Agency (TWRA), the Tennessee Aquarium, and the U.S. Fish and Wildlife Service, has stocked over 430,000 juvenile Lake Sturgeon into these waterways.
Stocking efforts have occurred in various locations, including the French Broad, Holston, and Tennessee Rivers, with specific releases into reservoirs such as Watts Bar and Old Hickory Lake on the Cumberland River. The juvenile sturgeon released were hatched from eggs collected from healthy populations in northern states like Wisconsin, demonstrating the collaboration required for this restoration. Biologists mark the stocked fish by removing a small bony plate, or scute, to identify the year of release and use tracking tags to monitor their growth and movement.
The Lake Sturgeon is a highly protected species in Tennessee, and its conservation status was recently downgraded from state-endangered to state-threatened due to the success of the reintroduction program. It is illegal to fish for or possess a Lake Sturgeon, and any caught incidentally must be released immediately and with extreme care. The Shovelnose Sturgeon is also protected in the state due to its visual similarity to the federally endangered Pallid Sturgeon. Anglers are encouraged to report any incidental catches of Lake Sturgeon to the TWRA, providing data on the location and size of the fish.