Eggstra, Eggstra

TVA Funds Help Partners Stock Tailwaters with Trout

Eyeballs.

Hundreds of thousands of eyeballs, like black flecks of pepper, stared up from translucent fish eggs spread on a mailing tray at the Erwin National Fish Hatchery in northeast Tennessee.

“It takes about 14 days for our fish to get what you’re seeing – 'strong eye' – and be sturdy enough to handle this process,” Tyler Hern, supervisory fish biologist, said.

Colt Brewer, facilities operations specialist, gently poured another sieve brimming with brook trout eggs onto a tray. Next to him, fish biologist David Teague prepared their mailing box with ice.

These eggs were bound for Dale Hollow National Fish Hatchery in central Tennessee, where over the next 12 to 18 months they would grow into sleek adult trout destined for dam tailwaters.

That’s where anglers casting from a riverbank or boat might first meet them.

The Tennessee Valley Authority has partnered to raise trout with the U.S. Fish and Wildlife Service’s Erwin and Dale Hollow hatcheries in Tennessee, and the Chattahoochee Forest National Fish Hatchery in Georgia, since 2013.

Each year, the hatcheries raise rainbow, brown and brook trout that the Tennessee Wildlife Resources Agency and Georgia Department of Natural Resources release into TVA tailwaters.

The agreement brings invaluable benefits to communities.

“When money comes to a place like Erwin National Fish Hatchery, it has ripple effects,” Hern said. “It allows us to produce several million eggs a year that support tailwater fisheries, which are huge economic drivers for the outdoor industry in our region.”

Recreational fishers generate about $75 for each $1 spent on hatcheries – totaling about $50 million for local communities.

And the benefits eclipse economics.

“People have these stories and experiences that you can’t put money to,” Shannon O’Quinn, TVA senior water resources specialist, said. “They’ll say, ‘This was the place my kids caught their first trout. It’s important to me. It’s important to my family. It’s a part of our community.’”

David Teague, fish biologist with the U.S. Fish and Wildlife Service, checks rainbow trout eggs at the Erwin National Fish Hatchery. (Photos by Susan Ehrenclou / TVA)

Experts in Egg Production

When TVA built its dams, chilly, clear tailwaters flowing from reservoirs proved ideal habitat for cold-water-loving trout. Today, TVA biologists and engineers work together to regulate flow and oxygenate the water as part of the Reservoir Release Improvement Program.

These conditions – and a decades-long partnership between TVA and the U.S. Fish and Wildlife Service – mean that trout thrive in world-class TVA tailwater fisheries.

Hern, Brewer, Teague, biological sciences technician Rebekah Ewing and deputy project leader Larry Sellers work together at the Erwin National Fish Hatchery to raise new generations of trout.

“From the outside, fish hatcheries sound pretty simple,” Hern said. “You’re a fish farm – you grow fish, you stock fish. But when you dig a little deeper, there’s a lot going on here.”

After the brook trout eggs were packed, a single cylinder of pearly orange orbs – 190,000 rainbow trout eggs, Teague said – remained.

“Just a few weeks ago, this whole room was full of eggs,” Hern explained. “It’s very seasonal, based on when the fish spawn."

Both temperature and photoperiod – how long the day is throughout the year – determine when female fish produce eggs and male fish produce milt.

And for that, this hatchery is perfectly positioned.

“When they chose this place, 120 years ago, they nailed it,” Hern said. “We get 1,000 to 1,200 gallons per minute of gravity-fed flow of water through the hatchery.”

The high-quality, constant-temperature water flows directly from an underground spring into 24 concrete raceways, or long rectangular tanks, where fish swim.

For eight months each year, different trout species spawn – although a single female fish releases eggs only once per year.

“It’s like a bell curve,” Hern said. “We take eggs from the beginning, the middle, the end of the spawn. Every egg that we produce goes through those jars and through the egg-picking machine, then it gets boxed up in these coolers.”

From there, Erwin National Fish Hatchery ships 18 million to 20 million trout eggs all over the country each year – to other Fish and Wildlife hatcheries, Tribal fisheries, state agencies, organizations such as Trout Unlimited and school programs such as Trout in the Classroom.

Trout eggs destined for cold, clear TVA dam tailwaters go to Dale Hollow or Chattahoochee hatcheries to grow into sleek fish.

And some fish live out their lives here.

“We don’t ship every egg because we have to keep some for the next generation,” Hern said. “That’s what the whole rest of the hatchery is dedicated to– rearing and maintaining those unique broodstocks so we can continue to produce the eggs, year after year.”

Rainbow trout swim in a raceway at the Erwin National Fish Hatchery.

Big, Healthy Fish

In tanks on the right side of the huge room, baby brook trout twine their thin bodies around one another in an effort to gobble up fine food sifting from a feeder above their tank.

Outside, rainbow and brook trout as long as one’s arm, their iridescent scales gleaming in the light, glide through raceways.

“We have a genetic management plan set up for the fish,” Hern explained.

That includes monitoring different strains of trout – which are kind of like breeds of dogs – and breeding carefully within each one for the healthiest animals.

Erwin is one of four broodstock hatcheries that focus on raising recreational fish species – the big rainbow, brown and brook trout that people love to catch. Another 12 federal hatcheries around the country focus on species in recovery, such as Gila, Lahontan cutthroat and greenback cutthroat trout.

“We just want big, healthy fish,” Hern said. “They’ve hit the lottery as far as hatchery fish go. It’s a pretty cushy life."

Rebekah Ewing, David Teague and Tyler Hern, of U.S. Fish and Wildlife Service, with Shannon O'Quinn, of TVA, at the Erwin National Fish Hatchery.

Partner Projects

In the four months they’re not actively spawning eggs, hatchery employees partner with TVA and other federal, state and Tribal agencies to monitor fish species such as reintroduced sturgeon, survey mussels throughout the Southeast and remove culvert barriers to fish and other migrating aquatic creatures.

“It’s all conservation science at work,” Teague said.

In addition to constant upkeep of pipes, raceways and filters, the team stays busy with plant, pollinator and bat habitat projects the public can tour at the Erwin Hatchery, too.

And they’ve started a mussel program, beginning with the pocketbook mussel, Ewing explained, so they can raise imperiled mussels in coordination with other state and federal agencies.

A lot has changed over the century of Erwin Fish Hatchery – but a lot has stayed the same, including the role of partnerships.

“That’s the driving force of why this hatchery has been here so long – because of the partnership with TVA and the Corps of Engineers and the tailwater fisheries,” Hern said. “What keeps the lights on is this project with TVA and the similar one with the Corps.”

Colt Brewer, of Erwin National Fish Hatchery, packs brook trout eggs to ship to Dale Hollow Fish Hatchery.

A Legacy of Fisheries

What starts as a clear sphere with two dots for eyes becomes a frisky, wild fish.

That fish becomes an experience for a fly fisher, a memory for a child who will grow up to value these waters, a draw for recreational fishers from across the country to visit TVA’s tailwaters.

“That’s 190,000 experiences and stories,” O’Quinn said, peering into the shine of the rainbow trout tank full of eggs.

Hern nodded.

“The hatchery system is remarkable,” he said. “We’re proud to be part of Erwin’s history and the community. There’s value besides just angling days created by number of fish stocked or eggs produced.

“There are people out there now who’ve fished in these tailwaters their whole lives. There’s a lot of legacy to these fisheries.”

Photo Gallery

Ewing stands with mussels at the Erwin National Wildlife Refuge.

Spring-fed water enters the first fish raceway at Erwin National Fish Hatchery.

Brook trout eggs ready to be shipped to Dale Hollow Fish Hatchery.

Baby brook trout at Erwin National Fish Hatchery.  

O'Quinn takes a peek at rainbow trout eggs.

Hern walks near an Erwin National Wildlife Refuge trout raceway that's being re-tented.

PHOTO AT TOP OF PAGE: U.S. Fish and Wildlife Service staff oversee trout egg production at the Erwin National Fish Hatchery, one of several hatcheries TVA funds to raise eggs and fish for its dam tailwaters.