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TVA specialists paddle kayaks along a section of the Hiwassee River known as Cutoff Reach, where they discovered an imperiled plant and rare mussels

The Race at Cutoff Reach

TVA Scientists Discover New Populations of Imperiled Species

One globally imperiled plant.

Four rare mussel species.

And reports of an aggressive, invasive algae threatening them all.

“We got really concerned, really fast, because extinction was on the table,” Adam Dattilo, Tennessee Valley Authority biodiversity program coordinator, said.

He and Todd Amacker, TVA’s aquatic endangered species biologist, knew this stretch of the Hiwassee River in southeast Tennessee well.

One section was home to the imperiled quillwort that Dattilo monitors. The other section, a remote, 9-mile stretch upstream called the Cutoff Reach, was ideal habitat for mussels that Amacker works to restore.

The rarity of the species and remoteness of the location make it a challenge to monitor.

It was one that Dattilo, Amacker and their partners from the Tennessee Wildlife Resources Agency were ready to face.

Outfitted with kayaks, wetsuits, snorkel masks and a map, the team launched into the shallow river riffles with two questions.

What was happening to the imperiled plants and animals?

And was it too late to save them?

Refuge for Rare Species

“This was the only known occurrence of Tennessee quillwort,” Dattilo said of the site on the Hiwassee.

And at that site, only 90 of those plants grew.

Tennessee quillwort, first described in 2003 by University of Tennessee botanist Jessica Budke, is cute.

Palm-sized, spiky, with stiff leaves like porcupine quills, it grows entirely underwater. Its roots grasp the fine gravel substrate on the river bottom. It reproduces like a fern, sending spores drifting on the current.

Quillwort thrives in this section of river.

As do populations of mussels, in remote sections of fast-flowing, warm water farther upstream.

“You can’t find as many mussel species anywhere in the world as you can in the American Southeast,” Amacker said. “It’s a region where mussel diversity is unparalleled.”

Yet searching for these plants and animals wasn’t easy. First, they combed the area where the algae had been reported. Then, they headed upriver.

“It required a lot of hiking. And dragging,” Amacker said.

Because sections of the river are so shallow, the kayakers had to heft their boats over thickly vegetated islands. Again. And again. And again.

“There was very much an expedition feel,” Amacker said. “How difficult it is to access is the whole reason there’s not a lot of data on what’s there in the river."

What did they find?

No invasive algae upstream or down, to everyone’s relief.

And a surprise.

The team found the mussels they sought.

The longsolid. The Tennessee clubshell. The Tennessee pigtoe. And the Tennessee bean.

And the imperiled quillwort? There was more of it than they expected.

Way more. A whole new population in the Cutoff Reach where it had never been seen before.

It took thinking outside the box, Dattilo said.

“That plant’s only ever been seen downstream … so people have only looked there,” he said. "But after this report of the invasive algae (downstream), I wondered if it was upstream, too.

“And then we ended up finding seven new sites for this plant, with well over a thousand individual plants.”

Finding more quillwort might mean it grows in more places than anyone thought – an intriguing discovery.

“Given how difficult it is to see, you can’t just walk around and say, ‘There, there,'" Dattilo said.

In fact, it takes quite a special approach.

“You have to stick your head underwater," Amacker said.

Sticking your head underwater through 9 miles of riffles and rocks proved daunting, but ultimately rewarding.

The team spotted healthy bunches of the endangered Ruth’s golden aster growing amongst rocks on the riverside.

And they spotted another new species for the area, a recently described flower new to science, the Hiwassee Goldenrod.

Before they left, they collected quillwort specimens for Professor Jessica Budke, University of Tennessee herbarium director, to identify. These plants will live in an aquarium at the Atlanta Botanical Gardens for study and safekeeping, just in case another threat emerges.

Not Out of the Woods

With this good news, it would be easy to conclude that all is well.

But Dattilo and Amacker see their success as a sign that we need more, not less, focus on imperiled species monitoring and research.

“People might say, ‘Well, now there’s a thousand plants so we don’t have to worry about this anymore,’” Dattilo said. “But (the quillwort) is only in one isolated place on Earth. Quillwort’s one of the rarest plants in the United States.”

Amacker nodded.

“And Aureola (golden riffleshell mussel) might be one of the rarest animals in the United States,” he said. “We didn’t find it on this survey. It might still be there. It might not. It hasn’t been seen since around 1992.”

Quillwort used to grow more widely, too.

A University of Tennessee-Knoxville record states that it was locally common in shallow, fast-moving riffles in the Southern Appalachian area. But since then, most of the population has disappeared.

This, Dattilo and Amacker said, is why TVA’s monitoring programs are vital.

“We provide that basic data piece so TVA can make decisions about how we manage,” Dattilo said, referring to TVA’s management of water flow and plant and animal populations.

“And that’s why having expertise in these plant and animal groups is so important,” Amacker said. “Being able to have someone in-house who can pick up a plant or animal and ID it to a species level is harder than it sounds and not something that every federal agency has.”

Looking To the Future

TVA’s aquatic surveys – along with ongoing monitoring by the Environment and Sustainability group – provide crucial information across the landscape and over the years.

“Gone are the days when you could just not pay attention and expect these things to stay here,” Dattilo said. “To keep these imperiled species on Earth, we really do need to manage everything with intent.”

With its three-pronged goals – energy, economic development and environmental stewardship – TVA is uniquely poised to act.

“TVA’s had a mission of stewardship since the agency was founded,” Dattilo said. “(TVA is) laying the groundwork for the next generation … and a way forward.”

Photo Gallery

The Tennessee quillwort, found in a section of the Hiwassee River in southeast Tennessee

An array of mussels found by TVA specialists who explored a section of the Hiwassee River in Tennessee

The Hiwassee River in southeast Tennessee

TVA specialists kayak along the Hiwassee River

TVA specialists record their findings as they search for plants and mussels in the Hiwassee River

A view of the Hiwassee River in southeast Tennessee

TVA biodiversity program coordinator Adam Dattilo records data while visiting the Hiwassee River

A TVA specialist carries his gear while walking in the river.

A TVA team member wears a snorkel to examine underwater species in the Hiwassee River
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Read about TVA’s work in environmental stewardship at the Biodiversity page.

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