“The students like touching the sturgeons; their scutes are really neat. They are rough and sandpapery, not slimy,” Anna George explained via phone.
George is director of the Tennessee Aquarium’s Conservation Institute. On Friday, she led a group of local homeschooled children in releasing 30 juvenile lake sturgeon into the Cumberland River at the Shelby Bottoms Nature Center in downtown Nashville. They were joined by Zeb Hogan, a National Geographic explorer and star of Monster Fish.
The Tennessee Aquarium has been working with the U.S. Fish and Wildlife Service and state agencies over the past few years to re-introduce lake sturgeon into both the Cumberland and Tennessee Rivers.
About their efforts, Hogan said via phone, “It’s a success story. It’s not the end of the road, because the populations are not self sustaining yet, but it’s a good start.”
George explained that they assigned two students to each fish, each of which weighed about five pounds and measured about 30 inches in length. The students helped guide the fish to help them get oriented in the river.
“They settle in pretty quickly,” said George. ”Then they swim off, and for a while you can see some of them breaching.”
She added, “Lake sturgeon can live to be 150 years old, so the fish these students helped release could be caught by their kids or grandkids in 30 to 50 years.”
Those 30 fish were raised in a federal hatchery in Georgia, from fertilized eggs collected from the wild in Wisconsin. Over the past 12 years, the Aquarium and its partners have released about 130,000 lake sturgeon into the state. George explained that more than 30 of the prehistoric-looking creatures were caught at monitoring stations in the fall.
George said the fish were of different ages and displayed good genetic diversity, so she is hopeful that the oldest fish will soon start reproducing, to establish a self-sustaining population. Sturgeon don’t become fertile until they are in their teens.
“All indications are that we have the right habitat for them, and we have documented upstream movement, so I think we will be successful,” said George. Lake sturgeon swim upstream to spawn, and according to George, they seem to be able to navigate the locks on the region’s dams.
The last credible lake sturgeon captures in Tennessee were in the 1960s. Their numbers declined due to commercial harvesting, pollution, and construction of new dams. In the 1880s, lake sturgeon were so plentiful that they were considered a nuisance, because their scutes could tear nets. They were purposefully fished out, and even burned as firewood, said George.
Times change, and thanks to the Clean Water Act, water quality has improved. In recent years, the Tennessee Valley Authority has adjusted the way it manages many of its dams, including preserving minium flows and oxygenating release water. ”One of the goals is to manage flows in the river to benefit aquatic biodiversity,” said Hogan.
“Sturgeon tend to do well when they are reintroduced into areas without harvest,” he added.
Two hours away, in Chattanooga, visitors to the Tennessee Aquarium now get a rare opportunity to see lake sturgeon up close. Guests can also marvel at alligator gar, giant whiprays, huge catfish, and other stunning examples of the world’s freshwater megafish at the new River Giants exhibit.
“The exhibit is exciting for me because I have spent the last five years traveling all over and studying these fish in the wild, and this is one of the only places in the world where people can see them in one place,” said Hogan, who helped kick off the exhibit this weekend (National Geographic is a collaborator).
Hogan said he hopes the exhibit will help educate people about these superlative fish, many of which are highly endangered.
The actual specimens on display came from far-flung locations, including other aquariums; the arapaima were confiscated from illegal collectors in South America.
“The logistics involved in getting these large fishes here is daunting, expensive, and not without risk to the fish,” said Hogan.
George added, “These really large fish are facing a common problem: how humans are altering the environment.”
This year is the Tennessee Aquarium’s 20th anniversary. George and Hogan hope that by the 40th anniversary, the state’s rivers will support healthy populations of sturgeon.
Check out the Tennessee Aquarium’s River Giants exhibit.
Brian Clark Howard is a writer and editor with NationalGeographic.com. He was formerly an editor at The Daily Green and E/The Environmental Magazine and has contributed to many publications, including TheAtlantic.com, FastCompany.com, MailOnline.com, PopularMechanics.com, Yahoo!, MSN and elsewhere. His latest book, with Kevin Shea, is Build Your Own Small Wind Power System.