By Laura Zuckerman
SALMON, Idaho (Reuters) - The U.S. government is seeking to close caves in national forests in the Northern Rockies to stem the spread of white-nose bat syndrome, a disease that has killed an estimated 5.5 million bats in 19 states and is spreading westward, officials said on Wednesday.
The fungus, which affects bats that hibernate in caves and mines, is mostly transmitted from bat to bat. But government scientists say it also can be transferred by caving enthusiasts who come in contact with infected bats or with the spores that linger after the syndrome has killed off a colony.
White-nose syndrome has not yet been detected in the Rocky Mountains, one reason the U.S. Forest Service is recommending ordering an emergency closure of caves as well as abandoned mines in national forests in Montana and northern Idaho and for some grasslands in the Dakotas.
"The bottom line is, it's a closure to protect our bat populations from a disease that is having a devastating effect where it has been found," said Kristi Swisher, threatened and endangered species program leader for the northern region of the Forest Service.
Under the government plan, which still must be approved by the regional head of the Forest Service and could go into effect as early as June, cavers and others could apply for a permit to explore caves if they agree to decontamination and other measures designed to protect bats.
White-nose syndrome has killed some 5.5 million of hibernating bats east of the Rockies since it was detected in New York in 2006, according to the U.S. Geological Survey. Government land managers have closed caves and abandoned mines in many states but have so far been unable to halt the spread of the disease.
Populations of insect-eating bats, estimated to save agricultural industries billions of dollars a year in pest-control costs, have dropped by more than 80 percent in the hard-hit U.S. northeast, research by the Geological Survey shows.
The northern region of the Forest Service, whose mandate includes the Northern Rockies, had proposed closing caves and abandoned mines last spring, igniting a debate between environmentalists and cavers, many of whom fiercely oppose closures in the West, where most caves are on federal lands.
"We are absolutely opposed to the blanket closure of caves, it's ridiculous," said Mike McEachern, officer with a caving club in Montana.
Word on Wednesday that the service was moving forward with a closure came the same day the Center for Biological Diversity filed a federal lawsuit seeking to force the agency to more fully disclose its plans to protect bats in the Northern Rockies.
Mollie Matteson, conservation advocate for the center, said the group will re-evaluate its legal filing when the Forest Service publicly releases the plan, expected in coming weeks.
(Editing by Cynthia Johnston and Sandra Maler)