A mysterious disease that has killed a million bats in nine states is headed toward Kentucky caves that hold three endangered species of the flying mammals, lawmakers in Washington were told Thursday.
"It is reasonable to expect that in the next three years or less, these key populations will be affected," Merlin Tuttle, founder of the Austin, Texas-based Bat Conservation International, told two subcommittees of the House Natural Resources Committee.
White-nose syndrome, as the disease is known, moved with shocking speed from the Northeast to Middle Atlantic states since being discovered three years ago, Tuttle said.
"This is serious, perhaps irreversible in terms of its harm to the environment and the economy," he said.
Experts estimate that the million bats killed so far would consume nearly 700,000 tons of insects in a year. Some of those insects spread disease or eat farm crops.
The economic impact on Kentucky of closing caves in an attempt to slow the spread the disease also was mentioned in the congressional hearing.
The annual "Crawlathon" at Carter Caves State Resort Park was canceled this year, meaning 600 to 700 people weren't filling up local motel rooms, said Peter Youngbaer of the National Speleological Society.
"There's a tremendous economic fallout to that," he said.
(Caves in the park that hold endangered Indiana bats have been closed, but others are open for tours.)
Scientists don't think people can "catch" white-nose syndrome, but there was a suggestion at the hearing that a public worried about the disease would stay away from commercial caves, hurting tourism.
That is of special concern in Kentucky, where Mammoth Cave National Park is a top destination and eight or 10 privately owned caves operate.
Tom Aley, a consultant advising the National Caves Association, which represents commercial caves, said in an interview that about 10 percent of the 4,000 people who work at commercial caves across the country are in Kentucky.
Several people testifying Thursday said more scientists should be put to work trying to figure out why bats are dying — and that will cost money.
Thomas Kunz, a Boston University biologist who is director of the Center for Ecology and Conservation Biology, said at least $10 million to $17 million is needed. About $5 million has been spent so far, a figure that one witness called "a drop in the bucket."
Tuttle emphasized that the money is needed immediately because the disease shows up in new caves every winter.
"We cannot have red-tape delays," he said.
Because the disease is in neighboring West Virginia and Virginia, Kentucky falls under a U.S. Fish and Wildlife Service recommendation to close border state caves to humans.
Scientists think that white-nose spreads from bat to bat as the tiny creatures huddle together in caves during winter hibernation. They suspect that people might carry the disease from cave to cave on equipment or the soles of their shoes.
The voluntary cave-closing advisory specifies that tours at commercial sites including Mammoth Cave may continue.
About 750,000 people visit Mammoth Cave each year, and 370,000 take one of several underground tours.
Steve Thomas, a park service ecologist, said he worries that some of those people might have recently been in a cave infected with white-nose syndrome.
The park is talking with the U.S. Fish and Wildlife Service about ways to protect bats. Caves in the park that have endangered species of bats are off limits, Thomas said, but stopping tours at other areas where bats are present is not under consideration.
One possibility is that people who go into the cave might step into some sort of disinfecting foot bath first, he said.
Aley and Dave Foster, director of the American Cave Conservation Association in Horse Cave, said foot baths could harm other species.
"Taking toxic substances into caves isn't a good idea," Foster said.
Brooke Slack, a wildlife biologist with the Kentucky Department of Fish and Wildlife Resources, disagreed.
It might or might not work, Slack said, "but right now, everybody is erring on the side of caution."
Aley said that commercial caves can help with research. Instead of closing, he recommended that they add a quarter to the price of every tour ticket, with the proceeds going to Bat Conservation International.
Bats that have the syndrome get a white fungus on their noses that spreads to their wings, scarring them. They wake so often during their winter hibernation that they burn up body fat. Sometimes, they fly out of their caves and flop around in the snow before dying.
In some caves, mortality reaches more than 90 percent.
Scientists have been unable to determine where the disease came from or how to stop it.
Officials first noticed the disease in New York in 2007. Then a caver came forward with a photo taken a year earlier that showed bats with white noses.
The government has closed all caves in national forests in the east, including an estimated 1,000 caves in Kentucky's Daniel Boone National Forest.
Caves also are closed in Great Smoky Mountains National Park, in Arkansas, Texas and other places.
Organized cavers are, for the most part, staying out of caves or sterilizing their equipment between trips.
Slack, the Kentucky wildlife biologist, is busy doing "baseline" research — sort of getting a picture of the state's bats before the disease gets here.
It already is on our doorstep sooner than expected, she said. She describes its arrival here as imminent.
"There's no reason for us to think we're going to escape," she said.