When Dr. Andreas Fath began this ambitious project, he entered the headwaters of the Tennessee River just a few miles downstream from Seven Islands State Birding Park. This 416-acre park occupies a peninsula embraced by a curve of the French Broad River, one of the Tennessee’s two primary feeder waterways (the other being the Holston River). More than 190 bird species have been seen here, but the site also holds significant aquatic importance as one of the release locations for juvenile Lake Sturgeon (Acipenser fulvescens) raised at the Tennessee Aquarium Conservation Institute.

One of thousands of baby Lake Sturgeon that recently arrived at the Tennessee Aquarium Conservation Institute. From just over an inch long, the sturgeon will grow to around six inches long before they’re released. (Credit: Casey Phillips/Tennessee Aquarium)

As Dr. Fath’s strokes carry him inexorably toward the river’s mouth in Paducah, Ky., he’ll be sharing the waterway with this ancient bottom-dwelling species, which first appeared during the Cretaceous Period more than 65 million years ago. In all that time, its armor-like body and whiskered head have remained largely unchanged, making it a kind of “living fossil.”

Lake Sturgeon like this one at the Tennessee Aquarium first entered the fossil record more than 65 million years ago. They have remained largely unchanged since the age of the dinosaurs, leading some to refer to them as a “living fossil.” (Credit: Tennessee Aquarium)

So in addition to the unprecedented water quality analysis he is conducting and the likely possibility that he will set another world record with the completion of his journey, Dr. Fath has at least one more feather to place in his cap: Swimming with dinosaurs.

The Lake Sturgeon was once plentiful in the Tennessee River, but it all but disappeared in the 20th century due to a combination of threats, including over-fishing, pollution and large-river alterations like dams that prevented it from reaching its spawning sites. Thanks to the Tennessee Aquarium Conservation Institute and its partner organizations, however, more than 200,000 juvenile Lake Sturgeon have been raised and reintroduced to their native waterway since stocking began in 2000.

Students release juvenile Lake Sturgeon raised at the Tennessee Aquarium Conservation Institute. Since the institute’s propagation program began in 1998, hundreds of thousands of these ancient fish have been raised and released in the Tennessee River. (Credit: Tennessee Aquarium)

Even the earliest sturgeon released through this program may not be old enough yet to begin reproducing. Male Lake Sturgeon don’t spawn until they reach 15-20 years old, and females until they are 22-33 years old. Nevertheless, the conditions in the river have improved dramatically in recent decades thanks to Tennessee making it illegal to fish for Lake Sturgeon, improved water quality as a result of the historic Clean Water Act of 1972 and dam improvement plans implemented by the Tennessee Valley Authority. As a result, many of the juveniles and young adult sturgeon sharing the river with Dr. Fath could still be swimming in the same waters 150 years from now.

Tennessee Aquarium Conservation Institute icthyologist Dr. Bernard Kuhajda holds a Lake Sturgeon. In the wild, Lake Sturgeon can grow to more than seven feet in length and live for more than a century. (Credit: Tennessee Aquarium)

For all their ancient heritage and resilience, even Lake Sturgeon would be impressed by Dr. Fath’s ambitions in swimming the entire river. To reach its spawning sites, a Lake Sturgeon travels an average of 62 miles. By the time he reaches Paducah, however, Dr. Fath’s strokes will have carried him more than 10 times that distance. That’s a journey that would drop even a dinosaur’s jaw in amazement.