All caves at El Malpais National Monument in New Mexico have been closed to humans due to concerns over white-nose syndrome, a deadly disease that is sweeping through bat colonies in the eastern United States.

While nearly all of the caves in the park have been closed for some time, Superintendent Kayci Cook Collins says the five caves - Junction, Xenolith, Big Skylight, Four Windows and Braided – that have remained opened are now closed to the public.

“Federal and state agencies in New Mexico are very concerned about the spread of the fungus, Geomyces destructans, which causes white-nose syndrome in bats,” said the superintendent in a prepared release. “The disease has already killed more than 1 million bats in the northeastern United States and has spread from New York State all the way to northwest Oklahoma in four years.”

Officials aren't entirely sure what causes the fungal disease or how to manage it. Nor do they know whether the disease originated in the United States or came over from Europe, where a similar fungus exists on bats, or whether there are pockets of naturally immune bat populations.

“Researchers believe bat-to-bat contact is one of the ways the disease moves from cave to cave, however the disease may also be spread from cave to cave by humans on their caving gear,” the El Malpais superintendent said.

The recent discovery of the disease in Oklahoma could easily threaten bat populations at El Malpais, she said.

“The (bat) species that tested positive in Oklahoma, the Cave myotis, is the first uniquely western species to contract the Geomyces fungus,” Superintendent Collins said. “And, more importantly, the Cave myotis is found at El Malpais.”

Research is under way to see if the fungus might already be present in monument caves.

“We have no evidence that the fungus is present in our caves, however we have been doing research over the summer and are currently testing cave soil samples to see if the Geomyces strain is here,” she said. “There are several other bat and cave research projects we hope to get under way later this year and next spring that will add to the information we are currently collecting.”

While testing for the fungus and monitoring cave environments is the prime focus of the ongoing and future research efforts, Superintendent Collins said the monument is also seeing which caves do not have bat colonies.

“Caves that have maternal colonies, are bat hibernating sites or have agency species of concern must be closed,” she said. “Once we have more solid information from our researchers, we will look at recreational caving options.”