A rare cave-dwelling fish is shedding new light on how farmers are improving water quality through cover crops and nutrient management.

University of Missouri Extension and the Missouri Department of Conservation (MDC) say new nests of grotto sculpin are growing in caves in southeastern Missouri.

The small, endangered fish lives only in Perry County caves. MDC biologists recently found 11 egg nests in seven of the county’s 15 major caves. MDC has researched grotto sculpin for more than a decade.

MU Extension natural resources engineer Frank Wideman says improved water quality likely accounts for the increased numbers. This is the first time MDC found reproduction of the fish deep within the caves. Adapted to live in the dark, the rare fish is pale from lack of pigment and may have small eyes.

Wideman helps farmers learn how to keep pollutants from reaching the water system through practices such as cover crops and improved nutrient management.

About three-fourths of the water in Perry County’s karst lands passes through channels in the rock of the county’s vast underground cave system. Streams and sinkholes feed into the caves.

The Perryville area contains “tens of thousands, if not hundreds of thousands, of sinkholes,” Wideman says. Sinkholes, dips in the land’s surface, carry runoff surface water to cave passages and underground streams.

Perry County’s karst land area includes springs and three creeks are the outlets for the underground water system. Some sinkholes and creeks go both ways. Heavy rainfall causes flash flooding, making the area’s caves unsafe and uncertain for spelunkers. These events rush farm chemicals and soil into the water system.

Farmers in Perry County work to improve the county’s water through no-till cropping systems, cover crops and nutrient management, Wideman says.

Farmers have stabilized sinkholes by planting cover crops to prevent soil and nutrients from washing through gullies into sinkholes leading to caves. They plant grass buffer zones as barriers around sinkholes. The grass filters out pollutants before they enter the water system. Wideman estimates that sinkholes are present in almost half of the prime farmland in Perry County and properties within the city of Perryville.

“They might be very useful chemicals in crop fields, but once they are in the cave system, they’re pollutants,” Wideman says.

Wideman says Perry County farmers grew 6,000 acres of cover crops last year as part of a state cost-share program that establishes a Soil and Water Conservation District (SWCD) in each county. MU Extension and its partners, including SWCD and the USDA Natural Resources Conservation Service, offer schools on why and how to grow cover crops. MU Extension strip trials in Perry County and other parts of the state help researchers study what works best for specific crops and regions.

Increased awareness extends beyond the rural community, Wideman says. Perryville city officials practice safe drainage. They encourage lawn owners to bag their grass clippings for pickup to keep nitrogen in the clippings from entering the water system. They work with automotive and manufacturing businesses to encourage safe chemical disposal.

City parks contain covered barriers over sinkholes to prevent park visitors from falling into the caves and running water below. The flow of good-quality running water can be heard through the barriers thanks to partnerships between MU Extension, SCWD, the city of Perryville and others, Wideman says.

Go to striptrial.missouri.edu to learn about MU’s strip trial program and crops.missouri.edu/covercrops to learn about cover crops.

To learn about the SWCD cost-share program, go to dnr.mo.gov/env/swcp/service.

To learn more about the grotto sculpin, go to fws.gov/midwest/news/682.html.

RARE CAVE FISH – Nestings of the rare grotto sculpin, found only in Perry County, Mo., are increasing as a result of improved water quality through cooperation of MU Extension and other groups, including the Missouri Department of Conservation. Photo courtesy Missouri Department of Conservation