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Saving the Last Great Places Under Earth

Scientists have learned that protecting karst ecosystems has direct benefits for humans.

By Jay Harrod, April 2006

“This stuff really stinks,” says Mike Slay as he baits a pitfall trap with rancid Limburger cheese. Slay, a karst (or cave) ecologist for The Nature Conservancy in Arkansas, is placing traps in hopes of catching troglophiles and troglobites.

“Troglophiles are animals like salamanders that can spend their entire life in a cave but can also be found on the surface,” Slay says. “Troglobites are found only in caves. Usually, they have no eyes or pigment.”

Slay explains that in a couple of days he’ll return to check the traps and will find as many as 20 beetles, flies and other cave-adapted invertebrates in each one. “A lot of the cave species eat carrion or guano – bat feces. So if you put something out that stinks, it’ll attract these animals,” he says.

On this particular day, Slay is monitoring – or counting animal species – in northwest Arkansas at Bear Hollow Cave, one of about 20 caves the Conservancy owns throughout the Ozark Mountains of Arkansas, Missouri and Oklahoma. Monitoring methods vary, Slay says, depending on the cave or targeted species. When monitoring Ozark cavefish, a species that’s known to exist in the Ozarks and nowhere else on Earth, Slay and a partner will don wet suits, scuba masks and fins and swim through underground pools with flashlights to count the endangered fish.

“Normally we don’t take salamanders or crayfish,” Slay says. “We usually take things you can’t identify in the field.”

Knowing the number of cave species is not the sole desired outcome of the Conservancy’s karst work in the Ozarks – it’s what guides it. This understanding of the population and location of rare cave species guided Conservancy scientists as they developed a list of 70 priority sites where the organization focuses its efforts. The Conservancy’s efforts are usually geared towards minimizing threats to the karst ecosystem and the animals that live there, but also threats to groundwater vital for humans.

“Karst terrain is porous and fractured, meaning that after rains pollutants can enter cave systems quickly and unfiltered,” Slay explains.

Tim Snell, the director of Ozark conservation programs for the Conservancy in Arkansas and the individual who launched the state’s karst program seven years ago, says working with landowners and developers is critical to protecting the karst ecosystem. Snell points out the success the Conservancy has had working with two residential developers at the small town of Cave Springs, about 15 miles west of Springdale, Ark. The Conservancy and the Arkansas Natural Heritage Commission worked with the developers to protect 50 acres of the 300-acre project directly above the cave or in the critical water recharge area for the cave, which harbors the largest population of Ozark cavefish as well as gray bats, also an endangered species.

“It’s a win-win situation for everyone,” Snell says. “The donated land is a tax deduction for the developers, it increased the size of Arkansas Natural Heritage’s Cave Springs Natural Area, and it will certainly help protect the cave.”

Slay is also working to identify the groundwater habitat where Cambarus aculabrum, a cave crayfish known to exist only at four sites in Benton County, Ark., lives. Waste Management Inc., which owns a landfill in Tontitown, the Northwest Arkansas Airport Authority, and the Arkansas State Highway Department are funding the study.

Both Snell and Slay say working with other agencies and organizations is what generates conservation results. “We regularly conduct inventory studies at caves owned by the National Park Service, the National Forest Service, Arkansas Game and Fish Commission, and private landowners,” Slay adds.

A good example of partnership work at its best, they say, is at Sherfield Cave and its main watershed, Smith Creek. Through a bargain sale the Conservancy purchased 1,226 acres above Sherfield Cave, where the state’s largest colony of endangered Indiana bats hibernates each winter. And a protection agreement on a private landowner’s adjacent property that harbors the cave’s main entrance limits potentially fatal disruptions to the bats during hibernation. Smith Creek, which is the Conservancy’s newest nature preserve in Arkansas, also connects the 1.2 million-acre Ozark National Forest and the 95,000-acre Buffalo National River Wilderness Area, protecting forest habitat for gray bats, black bears and elk, as well as critical foraging and roosting sites for the Indiana bats.

The ecological benefits of the preserve caught the attention of the National Fish and Wildlife Foundation, which, in April 2005, unveiled a new partnership with Wal-Mart, “Acres for America.” As part of the program, Wal-Mart pledged $35 million over the next 10 years to purchase one acre of priority wildlife habitat for every acre it develops. The National Fish and Wildlife Foundation chose the Conservancy as one of five initial grantees, and granted $400,000 for the Smith Creek preserve.

“We used to think that if we owned a cave entrance the cave was protected,” Snell says. “Through science, we’ve learned that we must consider the entire landscape, which affects the health of caves.”

These lessons, Snell says, have prompted the Conservancy to create materials and workshops designed to educate landowners and local governments about the fragile and precious landscapes below the surface in much of the Ozarks.

“We teach them ways in which they can protect their cave and their groundwater,” Snell says. “We also work to create buffers of trees and vegetation around cave watersheds, which can help filter pollutants. We erect fencing to help keep cattle out of streams, which can negatively affect the health of caves in the area. We help government agencies develop forest management plans that take into consideration the underground landscape. And we’ve always worked to protect caves from incompatible – and oftentimes illegal – human entry, which can harm cave species.”

Through science, Snell says scientists have also learned that protecting karst ecosystems has direct benefits for humans. For the past five years, the karst program team has worked with the Arkansas Department of Environmental Quality to conduct sample studies to identify threats to groundwater. “These studies obviously help us determine threats to caves and cave animals as well,” Snell adds.

As Snell discusses the karst program, his passion for the work is obvious. “It’s a very unique and beautiful ecosystem. It just happens to be underground. Glimpses into it are a rare treat.”

Snell also stresses the importance of visitors respecting karst systems. His first recommendation for people who want to see this amazing underground world is to visit a tour cavern, several of which are operated throughout the Ozarks and some of which even offer “wild cave tours” that cater to the more adventurous.

“If, though, someone still wants to get into caving, I’d definitely say that person should contact a local grotto – or caving – club,” Snell says. “In addition to teaching people how to protect the cave, they’ll also teach techniques and provide information that can mean the difference between life and death. Caving can be extremely dangerous.”

For more information about the Conservancy’s Ozark karst program, visit For more information about tour caves in Arkansas, visit

Learn more about the Conservancy's karst work in Arkansas.

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