Biologists say there's new hope for struggling bat populations in Canada following laboratory and field trials that treated white-nose syndrome with a common North American bacteria.

Researchers at Georgia State University started using the bacteria Rhodococcus rhodochrousin in laboratories to inhibit the growth of fungus that causes white-nose syndrome in 2012, The Nature Conservancy said in a news release. 

This winter U.S. Forest Service biologists conducted field work in caves in Kentucky and Missouri. They found 150 bats survived.  

"It looks like bats were able to survive with the help of the bacterium so it's promising," says Karen Vanderwolf, a bat conservation specialist with the Canadian Wildlife Federation in New Brunswick.

"It's more promising for western populations that have not yet been infected by the disease. - Karen Vanderwolf, Canadian Wildlife Federation

The syndrome arrived in Canada just five years ago but it has decimated populations. It's estimated to have killed 5.7 million bats in Canada and the United States. The fungus attacks bats when they're hibernating, penetrating their skin, causing dehydration and burning off the fat reserves they rely on to survive the winter.

Too late for Maritimes

The research is still preliminary and Vanderwolf says she doesn't expect this treatment will be implemented right away in Canada.

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White Nose Syndrome kills thousands of bats, but new research in the United States hopes to offer a cure. (Submitted by Hugh Broders)

"Here in the Maritimes, we've already had such substantial mortality that this treatment is a little too late for us. It's more promising for western populations that have not yet been infected by the disease."

This winter Vanderwolf said researchers in New Brunswick only found 13 bats in 10 caves where just a few years ago there were 7,000. In Nova Scotia, the bats' rapid decline resulted in the province's three species of bats — little brown bats, northern long-eared bats and tri-coloured bats — being added to Nova Scotia's list of protected species.

Hugh Broders, a biologist at Saint Mary's University in Halifax, said the best-case scenario in mainland Nova Scotia is a 98.5 per cent reduction in bats since the fungus hit the province about three years ago.

"We could be looking at the extirpation of each of the bats that are in Nova Scotia, which is a huge loss to the biodiversity of this province," he said. "These animals are predators of insects. There could be cascading effects for increased insect numbers of some species." 

Up until now, there's been no treatment or vaccines to curb the disease. 

"But at the same time, we need to be cautious. There's still a lot of information we need to collect and interpret on the actual practicality of the substance they're using on a significant scale," he said.  

Vanderwolf has been collaborating with the American researchers and sending them cultures of more than 30 types of fungus to determine if the bacteria they were working with has the potential to affect other species in cave ecosystems.

"It's not just bats we have to worry about, it's all the other species that are present in caves. We don't want to kill them off to try to save the bats."

Vanderwolf hopes the bats that have survived the syndrome up until now have some type of physiological resistance. Female bats reproduce slowly, giving birth to only one pup a year. But Vanderwolf hasn't ruled out a comeback.

"I wouldn't count them out just yet," she said. "It is possible that the population could come back but it would take a long time."