Tennessee Aquarium and partners hope to snatch darter from brink of extinction

Tennessee Aquarium and partners hope to snatch darter from brink of extinction

May 19th, 2012 by Pam Sohn in News

Anna George, director of the Tennessee Aquarium Conservation Institute, and Patrick Rakes, co-director of Conservation Fisheries Inc., and Rebecca Xiques, fisheries technician with CFI, left to right, release Conasauga Logperch into the Conasauga River on Friday. Almost two years ago, researchers from the Tennessee Aquarium and the U.S. Fish and Wildlife captured several specimen of the Conasauga Logperch, one of the rarest darters in North America. On Friday, after a long process of breeding and building a small population of the endangered fish, the researchers released a group of young logperch back into the river. Middle school students from Valley Point Middle School in Whitfield County were on hand for the release.

Photo by Jake Daniels/Times Free Press.

CONASAUGA LOGPERCH

• The Conasauga logperch is one of the rarest darters in North America. The 6-inch logperch lives where the pristine Conasauga water flows out of the Cherokee National Forest into Polk County, Tenn., then ripples southward into North Georgia.

• It is a brownish fish with tiger stripes, and it uses its piglike flattish, pointy snout to flip pebbles on the crystal clear river bottom, then eats the insects it finds beneath.

• In the wild, it lays its eggs in the sand, so it needs a really clean, clear river.

• It is listed on the federal Endangered Species List.

• The Conasauga River, 40 miles east of Chattanooga, ranks fourth among U.S. rivers for harboring the highest number of imperiled aquatic species, including snails, mussels and fishes.

Source: Tennessee Aquarium Conservation Institute, U.S. Fish & Wildlife Service

ENDANGERED SPECIES

• 597 animals listed as threatened or endangered in the U.S.

• 92 in Alabama

• 38 in Georgia

• 66 in Tennessee

Source: U.S. Fish & Wildlife

TENNGA, Tenn. -- Nearly two years ago, Tennessee Aquarium researchers and other conservationists snorkeled the upper reaches of the Conasauga River looking for one of the rarest darters in North America -- the 6-inch Conasauga logperch.

At the time, the researchers estimated there were fewer than 300 of the small tiger-striped fish anywhere on Earth. And they all lived in this pristine 30-mile stretch of the Conasauga where it flows through the Cherokee National Forest.

On Friday, Endangered Species Day, there was better news: The count is going up.

Today there are about 1,000 Conasauga logperch on the planet.

The nine caught that August 2010 afternoon and two more belonging to Conservation Fisheries in Knoxville became the Adams and Eves of the aquarium's newest conservation repopulating effort.

And this month, the researchers began releasing the 700 1-year-old Conasauga logperch offspring in the same crystal clear pools where their parents had grown up.

"Happy Endangered Species Day!" shouted Anna George, director of the Tennessee Aquarium Conservation Institute, after she watched a handful of large-eyed darters timidly edge toward freedom during one of the releases.

"It's a lot of fun to see them come out of the bag," George said. "They looked a little scared for a moment, but then they started acting like a fish should."

Patrick Rakes, co-director of the Conservation Fisheries, whose "wet thumb" helped ensure the success of the captive breeding program -- a world "first" -- waded out of the Conasauga with a big grin.

"It's always fun to do this," he said. "I like to think we might be making a difference -- small as it might be."

Teaching science

It was also a "first" for about 30 seventh-graders from Whitfield County's Valley Point Middle School.

The youngsters, on a science field trip to snorkel with the U.S. Forest Service, met George and Rakes and the tiny endangered fish.

The school's science classes include a creek testing program on Little Swamp Creek near Dalton, and Friday's snorkeling "fish-watching" day on the Conasauga in Polk County got an extra but unexpected spark with the logperch release.

"This is a big surprise for all of us," said science teacher Amber Croy, smiling at the students' oohs and aahs as George told them the story of catching and propagating the rare fish.

The babies, she told them, were raised in Tennessee Aquarium fisheries tanks in Chattanooga and in tanks at Knoxville's Conservation Fisheries, a nonprofit organization established by Rakes and J.R. Shute.

George and the Institute staff did genetic studies on the parent fish -- nine males and two females -- as well as on the brood.

The results offered another scientific surprise.

Normally in small populations of a species, there is limited genetic diversity, and that can often hasten the demise of a species.

But the Conasauga logperch family has broad diversity in its genetics, she said, adding that each of the parent fish contributed to the spawn.

The actual breeding and spawning for the repopulation was handled by Conservation Fisheries. The organization has a goal of restoring fish populations that have been eliminated because of pollution or habitat destruction.

To do that, Rakes and Shute propagate the region's rarest fishes.

They also monitor the status of populations of rare fishes in Tennessee, Alabama, Georgia, Kentucky, North Carolina and Virginia.

And they produce fishes for use in toxicity testing. Policymakers use the tests to refine water quality standards to better protect rivers and streams.

What's next?

In coming weeks, the researchers will release all of the logperch babies at different spots in the Conasauga.

The youngsters are marked with what George calls "fish tattoos," that are color-coded for future monitoring.

Almost two years ago, researchers from the Tennessee Aquarium and the U.S. Fish and Wildlife captured several specimens of the Conasauga Logperch, one of the rarest darters in North America. On Friday, after a long process of breeding and building a small population of the endangered fish, the researchers released a group of young logperch back into the river. Middle school students from Valley Point Middle School in Whitfield County were on hand for the release.

Photo by Jake Daniels/Times Free Press.

Between that monitoring and the genetics work and other research, George hopes to someday know why the Conasauga logperch only lives here on one small stretch of mountain river.

It could be, said George and Rakes, that this small pristine reach of the Conasauga is the only place good enough for them.

In the meantime, said Rakes, researchers now know how to propagate the little darter, and if anything bad happens to the river, the ongoing propagation effort could maintain the species.

He also has high hopes that the Dalton youngsters who saw the incredibly rare fish will remember it as they mature.

"We'd like to think the kids will grow up to be become politically active" after learning about the fish and watching it, he said. "Most people don't realize the rivers in the Southeast are really messed up. There are very few really clean rivers left."