MANCHESTER, Tenn. (CN) – The pond lies in the Tennessee barrens, a flat region of the Volunteer State that stretches across five counties and is home to cattle farming and the Bonnaroo Music and Arts Festival. It sits below a highway carrying 18-wheelers, bordered by willow trees and a grove of bamboo. About the size of two backyard pools placed end-to-end, the pond is easy to miss.
On Tuesday, after weeks of waiting, a group of biologists and conservationists returned about 400 endangered Barrens topminnows to one of their last remaining homes in the world: the Summitville Mountain Spring near Manchester, Tennessee.
The pond is fed by an underground stream that comes out of a rock face. On the other side, a concrete escarpment gives the pond a two-foot drop off before the water trickles under the highway, past a field of grazing cattle, and flows into West Fork Hickory Creek.
That concrete drop-off is key – it’s what separates the colorful Barrens topminnows in that pond from the invasive western mosquitofish lurking downstream.
Originally, the western mosquitofish was introduced to the barrens to eat mosquito larvae, like it has been introduced the world over. But the mosquitofish attack the topminnow, eat their young and prevent them from reproducing. Once mosquitofish move into an area, it’s only a matter of time before the Barrens topminnows there cease to exist.
But this pond is far from perfect. Four times in the last decade and a half, rescue teams needed to snatch the topminnow from this location as drought descends and the pond dries up.
The Tennessee Wildlife Resource Agency keeps an eye on the pool. If the water level drops, it calls the Tennessee Aquarium in Chattanooga and Conservation Fisheries in Knoxville to rescue as many Barrens topminnow as they can.
On Oct. 3, with a drought looming, a rescue team had brought a 10-foot seine net and pulled fish from the pond. Tennessee Aquarium took 200 and Conservation Fisheries took another 200.
When the U.S. Fish and Wildlife Service placed the Barrens topminnow on the endangered species list last month, 200 of the fish were not swimming in the wild. They were kept in two, black 140-gallon vats in the Tennessee Aquariums’ quarantine facility in Chattanooga, next to a few saltwater rays and near a 38,000-gallon saltwater tank holding a couple of sandbar sharks.
On Tuesday morning, aquarists at the Tennessee Aquarium loaded the fish in three water-filled plastic bags, and lifted a cooler into the back of the pickup truck belonging to Matt Hamilton, the aquarium’s curator of fishes.
After Hamilton made the hour-and-a-half drive to Manchester from Chattanooga, representatives from the Tennessee Wildlife Resources Agency and the U.S. Fish and Wildlife service were already there, along with Conservation Fisheries.
Speaking by phone a few days before the drop, Pat Rakes, co-director of the Knoxville-based Conservation Fisheries, said the Tennessee River watershed is one of the most biologically diverse waters in the world.
“If you look at anything, salamanders, mussels, crayfish, any of them, the Tennessee watershed is one of the most diverse in temperate latitudes,” Rakes said.
When he came to the University of Tennessee back in the 80s, Rakes’ professor suggested he study the Barrens topminnow.