Building up mussels at Inks Dam National Fish Hatchery
A freshwater mussel at the Inks Dam National Fish Hatchery. Staff photo by Daniel Clifton
EDITOR DANIEL CLIFTON
The Inks Dam National Fish Hatchery is growing something new: Texas fatmucket, Texas pimpleback, and Texas smooth pimpleback mussels.
Or, it’s trying to.
“It’s not as easy as you might think,” project leader Jeff Conway said. “These are not cultivated that much, and we’re still trying to figure out what will work.”
Along with the Uvalde National Fish Hatchery and San Marcos Aquatic Resources Center, the Inks Dam hatchery landed a contract through the Texas Comptroller’s Office to scientifically assess whether Texas freshwater mussels can be cultivated as a means of keeping them off the federal endangered species list. Currently, three of 15 species of freshwater mussels are on the Texas threatened species list.
Freshwater mussels require a steady flow of quality water to survive, which makes them good indicators of environmental health. Central Texas mussels, particularly those in the Colorado and Guadalupe river basins, struggle with problems of drought, sedimentation, and chemical contaminants.
An important cog in Mother Nature’s circle of life, mussels are a food source for other aquatic creatures. If the mussels aren’t healthy, the fish aren’t either, which is where the Inks Dam National Fish Hatchery comes in. The problem with mussels is that not much is known about raising them.
“With fish, there’s a lot of history,” said Daniel Bailey Gaines, a fisheries biologist at the hatchery. “But with mussels — particularly with the species we’re working with — there’s just not a lot of information out there.”
During the first year of the project, Conway and Gaines produced two mussels from more than a thousand larvae, about the norm in the wild as well, although no one really knows for sure. The second year, Gaines experimented with a different method and came away with zero. This year, however, as Gaines peered through a microscope and counted the potential mussels, he and Conway smiled. The numbers were looking good — so far. Now, they have to grow the larvae into adults.
Mussels are not the only mission at the hatchery. It also provides channel catfish for 10 Native American tribes and nations in New Mexico and Arizona.
“Last year, they put the value of (the channel catfish) program between four (million) and five million (dollars) for the native groups,” Conway said. “That’s pretty significant.”
The fishery also tends a refuge population of Clear Creek gambusia, a minnow-size endangered fish found in a spring that feeds the San Saba River.
The facility was built by the Public Works Administration and opened in 1940. Its original purpose was to supply fish to the Highland Lakes. In the 1950s and ’60s, the focus changed to farm pond production of channel catfish and largemouth bass, although it no longer raises bass. Stocking Native American lands began in the 1980s.
Cultivating mussels has proven to be among the hatchery’s biggest challenges to date. Part of the mussel mystery for scientists is how to recreate a system that provides the correct habitat for growth. Mother Nature knows, but she’s not sharing any secrets with Gaines and Conway, who struggle with replicating lake and river bottom environments.
The setbacks are real but part of the process, Gaines admitted. There’s no textbook or user’s manual for this one.
Conway shrugged.
“That’s why they call it research.”
Inks Dam National Fish Hatchery is located at 345 Clay Young Road in Burnet. It is open to the public 7 a.m.-3:30 p.m. Monday-Friday, except on federal holidays, and offers hiking, bird-watching, fishing, picnicking, and outdoor education.