Caves hold a hidden trove of biodiversity

A new species of Orconectes crayfish from Missouri was discovered by cave biologists

March 30, 2000
Web posted at: 11:43 p.m. EST (0443 GMT)

By Environmental News Network staff

Out of sight and, until recently, out of mind, cave-dwelling species in the United States have finally captured the attention of the conservation community.

For the first time, scientists have summarized the ecological and geographic patterns of obligate cave species, a population whose survival depends on a narrow lifestyle.

"Because they do not fit comfortably into the schemes of many ecosystems, cave-dwelling fauna tends to be very rare," David Culver, lead author of a new study on cave species. "Many of these species have been missing from data bases. We wanted to make this information available to state wildlife management agencies."

Nearly 1,000 species, mostly crustaceans, insects and arachnids, live exclusively in caves within the continuous 48 states. About 95 percent of the species are listed as vulnerable or imperiled by The Nature Conservancy, yet few are listed under the Endangered Species Act.

Because obligate cave species are concentrated in less than 2 percent of the continental United States, mostly in the southeastern states, Culver and colleagues were able to identify key areas of biodiversity. The information may be an important resource in future conservation efforts.

"Many of these species occur only within a single county," Culver said. "Some species occur in only one or two places."

Protecting caves is not enough to save cave species. Wildlife managers must also protect the land above the caves. "The way to protect any species is to protect its habitat," Culver said.

Caecidotea sp., a blind, aquatic, asellid isopod from Texas, is another cave-dwelling species

Nearly all cave species are vulnerable to disruptions of vegetation and drainage basins that surround caves. Deforestation near caves can decrease bat and rat populations, reducing the scat that many cave species depend on. Because caves usually contain water, protecting the surrounding watershed is also important, Culver said.

Scientists are particularly interested in cave-dwelling species because they have much in common with species that live in other extreme environments such as thermal springs and deep-sea vents.

"Cave species can tell us a lot about evolution, (particularly) why species loose certain traits," Culver said.

The majority of cave-dwelling species do not have eyes and are unpigmented due to their lack of exposure to sunlight. "An eye in a cave may use unnecessary energy," Culver said.

Such characteristics led communities in the 17th century to believe that white salamanders, which washed out of caves in eastern Europe, were baby dragons.

Culver's study is published in the April issue of Conservation Biology.

Copyright 1999, Environmental News Network, All Rights Reserved

New study finds warming trend in oceans
March 23, 2000
Ocean graveyards tell whales of stories
February 28, 2000
Ocean ranch could bring sustainable energy, food
September 29, 1999
Leaky seas drying up Earth, scientists report
September 17, 1999

Southeast groundwater pollution feared
Paradise found: Kartchner Caverns
Scientists to probe secrets of Mexican cave
Scientists to analyze species recovery plans
U.S. fine tunes habitat conservation plans

the biology of caves
The British Cave Research Association
Association for Biodiversity Information

Note: Pages will open in a new browser window

External sites are not endorsed by CNN Interactive.