Rare aquatic lichen makes a comeback in Fundy National Park

A threatened aquatic lichen is now making a comeback in the streams of Fundy National Park.

The eastern waterfan was designated as a threatened species in 2013 and officially listed under the Federal Species at Risk Act in 2018.

The dark purple lichen was thought to exist in only two streams in the park, but that's changed this year.

"We were starting to get an idea that there was more waterfan out there than we expected … this summer was really when we hit the mother lode so to speak," said Neil Vinson, acting ecologist at Fundy National Park. 

Ecologists at Fundy National Park and the Atlantic Canada Conservation Data Centre unexpectedly found more than  1,000 colonies along 28 streams.

Although new colonies have been found, the species is still considered threatened, he said. At least 10,000 thriving colonies are needed before the eastern waterfan can be taken off the list.

The team found the colonies during two weeks of dedicated searches this summer. They used high-powered flashlights to find the lichen because it often hides in dark corners of shady, undisturbed streams. 

"Even if it's daylight and it's a sunny day, there's not much light getting into the corners of these streams so we found a flashlight really helped find it especially when it was growing underwater," Vinson said.

The rare, leafy lichen is not a single organism, it's typically made up of a combination of fungus and algae or fungus and cyanobacteria. It's typically found in eastern North America and has been found in Quebec, Nova Scotia and New Brunswick.

It was likely threatened because it is sensitive to environmental quality, said Stephen Clayden, curator emeritus of Botany and Mycology at the New Brunswick Museum.

"They're good indicators of how environments are changing," Clayden said. 

"So whatever's in the air and rainwater or fog, or if they're in a brook, whatever's in the water, they can take that up and that makes them very sensitive to air pollution [and] water pollution."

But Clayden said it's possible the lichen was overlooked in the park.

"It's not a very conspicuous thing until you really get some experience in knowing how to look for it and where to find it," he said.

Vinson said he was surprised that there wasn't an extensive record of lichen in the park.

"It does seem curious that nobody found it when we found as much as we did," he said. 

"So then you have to wonder, is it just re-establishing after the history of logging and disturbance that occurred in the park?"

Vinson said the search for the rare lichen will continue inside and outside the park. 

"Most species-at-risk stories are kind of dour and there's never really good news to do with them," he said. 

"So it's nice to have a positive species-at-risk story, where instead of these things getting more and more endangered, we're finding one where we actually increase the numbers of species at risk."