The U.S. Forest Service is preparing to close thousands of caves and former mines in national forests in 33 states in an effort to control a fungus that has already killed an estimated 500,000 bats.
Forest Service biologist Becky Ewing said an emergency order was issued last week for caves in 20 states from Minnesota to Maine. A second order covering the Forest Service's 13-state Southern region should be issued later this month.
The sites will be closed for up to a year, she said.
The orders follow a March request by the U.S. Fish and Wildlife Service for people to voluntarily stay out of caves in 17 states.
Bats have been dying at alarming rates from what scientists call "white-nose syndrome," so-named because it appears as a white powder on the face and wings of hibernating bats. The problem was first spotted in New York and within two years has spread to caves in West Virginia and Virginia.
Researchers believe the fungus is spread from bat to bat, but they have not ruled out a human connection, said Dennis Krusac, a biologist with the service's Southern region.
"We don't have the answers at this point," he said. "If we have answers in a year or sooner, we can open them back up."
Biologists are concerned the fungus could wipe out endangered Indiana, Virginia and Ozark big-eared and gray bats.
Bats play a key role in keeping insects such as mosquitoes under control. Between April and October, they usually eat their body weight in bugs per night. The loss of 500,000 bats means 2.4 million pounds of bugs aren't eaten in a year, Ewing said.
New York caver Peter Haberland said organized caving groups shouldn't object to the closures.
"For a period of a year, most people can deal with that," said Haberland, who serves on the Northeastern Cave Conservancy's board.
He said the order should have little effect in the Northeast since just a few national forests there offer caving.
"A lot of caves are on private property," he said. "There is no jurisdiction from government agencies on private property even though there should be some."
Peter Youngbaer, white nose syndrome liaison for the National Speleological Society, another caving group, said it makes sense for the Forest Service to issue umbrella orders so it can communicate a clear message.
"There is a huge concern," he said. "The recreation aspect is probably the least of our concerns."
Yet many people who explore caves are not part of organized groups, so education will be key, he said.
The Forest Service order says people caught in a cave or mine face up to six months in jail and fines of up to $10,000. Ewing said Forest Service officials will enforce the bans.
Youngbaer said he isn't convinced humans help transmit the fungus, which kills the bats because it affects their hibernation habits, causing them to starve.
A study based on soil samples taken from 200 sites in 30 states should help resolve that question. Results should be available in September.
"There is no question that it's spreading bat to bat and spreading from bat to bat rapidly," he said. "If it turns out the fungus is living in the caves anyway ... humans moving around doesn't mean anything."
He said better funding from the federal government is needed to research the problem. Right now, thousands of research dollars come from donations by caving and other groups, he said.
Many of the caves in question are in the 919,000-acre Monongahela National Forest in West Virginia, which this week announced it would extend a ban imposed last year on access to caves. Last year's ban only affected caves considered to be at high risk for the fungus.
On Friday, the Indiana Department of Natural Resources moved to close caves on state-owned property. The disease has not been found in Indiana, but officials decided to close caves there until April as a precaution.
Last month, officials closed all of the caves in the Great Smoky Mountains National Park.
Krusac said the orders do not affect commercial caves on private property. Officials in the Ozark National Forest are debating whether to impose restrictions on wild cave adventures on the forest's Blanchard Springs Caverns, reported AP.