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Placing fish habitat pallet on pile.

Sunken Treasure

New Structures Serve as Long-Lasting Fish Habitat

Designing the perfect fish habitat means thinking like a fish.

Fish, like other animals – and humans – want a safe, sturdy home where it’s easy to raise a family and find food.

The only difference? A fish’s home is underwater, where many materials don’t last.

“When the (TVA) reservoirs were created, there was a lot of (timber) cover and habitat,” Shannon O’Quinn, Tennessee Valley Authority senior water resources specialist, said. “Over time, that dies out and decays.”

Luckily, engineers are on the case, building long-lasting artificial fish habitats that don’t degrade underwater.

TVA purchased 1,100 MossBack artificial fish habitat structures and, on a sultry spring day, helped staff from the Tennessee Wildlife Resources Agency and volunteers assemble them.

“This partnership with TWRA will provide more permanent habitat for the fisheries in Watts Bar,” O’Quinn said.

Mike Jolley, Tennessee Wildlife Resources Agency reservoir fisheries manager, agreed.

“We can put these in now and they should be there for well past our lifetimes,” he said.

Building fish habitat structures.

Volunteers joined crews from TVA and Tennessee Wildlife Resources Agency in assembling 1,100 artificial fish habitat structures destined for Watts Barr Reservoir.

Moving Pieces

Pieces clacked as builders tackled the 18 pallets of fish habitat awaiting assembly at the Hiwassee Wildlife Refuge.

“We're really excited to put together so much habitat for Watts Bar Reservoir,” Jolley said. “Habitat is one of the top three components of a fishery, outside of the people and the fisheries themselves.”

The habitat kits came with names that described their purposes – the MossBack Root Wad, Trophy Tree and Safe Haven.

Each kit provides structure and mimics natural habitat.

“This Trophy Tree is roughly 40 inches tall,” Jolley said. “It'll provide different kinds of habitat for juvenile fish. Even adult fish can hide out here and get a little bit of shade, and these are really good for spawning, too.”   

“Fish love structure,” said Will Barron, who works for MossBack, the federally contracted company from which TVA purchased the structures. “They feel safe in it. (The structures) have spaces here, and here and down here.”

He pointed to the notches where arms would flare out, building a PVC tree.

“We’ve got a 60-inch, a 40-inch and 20-inch that we can put at different depths,” Jacob Mowery, hatchery and habitat manager for the Tennessee Wildlife Resources Agency, said.

“We'll start the 20-inch in 5 feet of water. And then these,” Mowery said, patting the top of the 60-inch standing tree, “will end up in 20 feet.”

Most structures will stand vertically or lie horizontally in medium-depth water, where they’ll still be covered during TVA’s winter reservoir drawdowns.

Crappie, spawning bluegill and bass, among other fish, will feed, hide, ambush and spawn within.

“We have 40 sites from dam to dam, including tributaries,” Joey Root, Tennessee Wildlife Resources Agency reservoir manager, said. “It's definitely the biggest habitat project I've ever been involved in.”

Fish can find cover in the structures, which create over 6 acres of new habitat in Watts Bar Reservoir, TVA watershed representative Jess Wykoff-Carpenter said.

“It’s going to be awesome,” Mowery said, grinning at the construction around him.

Man smiles standing next to fish habitat.

Tennessee Wildlife Resources Agency reservoir fisheries manager Mike Jolley carries assembled structures to a staging area at Hiwassee Wildlife Refuge.

Getting Dirty

While the fish habitats look new now, they won’t for long.

That’s the point.

“The cool thing ... (the) top is rough,” Root said. “That’s going to allow for algae and macroinvertebrates to attach to it.”

That blend of algae and invertebrates is called periphyton – brown or green fuzz that grows on submerged tree trunks, docks and other underwater surfaces.

Periphyton is fish food.

While regular PVC pipes have a biocide film to keep algae from growing, this fish habitat is special.

“All the surfaces have a unique texture,” Barron said. “In a month or so, it'll be a living piece of habitat in the water.”

Woman connects pieces for fish habitat structure.

Cleveland State Community College student Julia Nichols adds crossarms to a fish habitat.

Go Fish

At the end of the workday, the building crew had put together about a third of the 1,100 structures – more than expected.

“It's awesome,” Jolley said, beaming at row upon row of spiky habitat structures. “It gets us way ahead in this project.”

The next step is to haul the structures – by trailer to the reservoir, and by pontoon boat to the deployment spots.

Some structures will be dedicated nursery habitat.

Locations and types of other structures are marked on interactive GIS maps of each TVA reservoir, which people can find on the Tennessee Wildlife Resources Agency website, Mowery said.

“People can put the coordinates on their depth finder or phone and go fish on top of (the structures),” he said.

TVA’s investment in these permanent habitats is a win-win-win.

For one, fish find new homes.

“This allows the Tennessee Wildlife Resources Agency to go to more sites each year, too, so it's a really good thing,” Jolley said.

And TVA can fulfill its mission of environmental stewardship as it partners with Valley conservation agencies.

“It wouldn’t have been possible without all the volunteers and TVA and TWRA,” Jolley said. “There's a lot of incredible effort and enthusiasm out here by everybody.”

Photo Gallery

TWRA personnel with fish habitat structures.

Tennessee Wildlife Resource Agency reservoir manager Joey Root and hatchery and habitat manager Jacob Mowery share a laugh with colleagues as work gets underway.

Putting together fish structures.

The new structures will create more than 6 acres of habitat in Watts Bar Reservoir, TVA watershed representative Jess Wykoff-Carpenter said.

Assembling fish habitat.

The structures create more permanent habitat for fisheries in the reservoir, TVA senior water resources specialist Shannon O’Quinn said.

Group stands in front of fish habitat structures.

The project’s building crew –  24 members strong – stands proudly amid the hundreds of newly assembled fish homes.

PHOTO AT TOP OF PAGE: Crew member Ashley Padgett adds a finished habitat to the mix.

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Learn about TVA’s work to monitor conditions in the region's waterways at the Water Quality page.

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Woman stands with fish habitat structure.

Homes for Fish

Interested in learning more about manmade habitats for fish? Check out TVA’s fish attractor guidelines.