Montana Public Radio

Climate Change Impacts Push Glacier Park Stone Flies To 'Threatened' Status

Nov 21, 2019

Two stone fly species found in Glacier National Park were listed as “threatened” under the Endangered Species Act Wednesday due to the impacts of climate change, according to a rule published by the U.S. Fish and Wildlife Service.

The two species, the western glacier stone fly and the meltwater lednian stone fly, depend on glacial meltwater in high-elevation alpine environments. But scientists estimate the famed ice masses and snowfields of Glacier National Park will have mostly disappeared by 2030.

“These species might be some of the first that go extinct because of climate change. They are literally the polar bears of Glacier National Park,” says Clint Muhlfeld, a research aquatic ecologist with the United States Geological Survey. He’s studied the two stone fly species for a decade and a half. His research informed Wednesday’s listing decision.

Both stone flies live deep in Glacier National Park. The western glacier stone fly has also been found in Grand Teton National Park and in the Absaroka-Beartooth Wilderness, and the meltwater lednian stone fly has been documented in the Bob Marshall and Great Bear Wilderness, and in tribal land in the Mission Mountains.

Diminishing meltwater from vanishing glaciers, along with warmer water and drought are forcing the species higher and higher in elevation in search of suitable habitat.

Researchers survey for stone flies in the backcountry of Glacier National Park, Sept 1, 2019. Two species of stone fly were listed as "threatened" due to warmer water, drought and diminishing meltwater from vanishing glaciers.
Credit Nick Mott / Montana Public Radio

“There’s basically nowhere to go,” Muhlfeld says. “They’re at the highest elevations of stream networks in freshwater ecosystems. So it’s a squeeze-play at the top of the continent.”

Muhlfeld says the flies serve as barometers for the health of mountaintop ecosystems — biodiversity hotspots that scientists are still working to understand.

“As these species decline and we lose species from these ecosystems, we unravel the resiliency of these systems to deal with rapid environmental change,” he says.

Usually, “threatened” status means heightened protections for habitat on which species depend to survive. A new Fish and Wildlife Service rule published in August cut back standards that designate critical habitat for species. Due to that rule change, the FWS said designating critical habitat for these stone flies was “not prudent” in its listing.

Muhlfeld says the flies live in national parks and wilderness areas — land that’s already highly protected.

“Unfortunately the most beneficial tool for conserving alpine stream biodiversity may rest in reducing human stressors, such as global carbon emissions which contribute to global warming, glacier decline, and loss of alpine habitats,” Muhlfeld says. “The threat’s more of a global phenomenon that on the ground at the local level managers can do very little to ameliorate.”

Endangered Species Act protection also comes with more federal funding for conservation efforts and mandates the creation of a recovery plan for the species. Protections go into effect 30 days from Wednesday.

A researcher surveys for stone flies in the backcountry of Glacier National Park, Sept 1, 2019. Two species of stone fly were listed as "threatened" due to warmer water, drought and diminishing meltwater from vanishing glaciers.
Credit Nick Mott / Montana Public Radio

The listing process took more than a decade. The federal government was petitioned in 2007 and 2010 to provide ESA protections for the two species. Then, the FWS proposed a rule in 2016 to list both species as “threatened.” But that rule was not finalized until this week, after a lawsuit from the Center for Biological Diversity.

The CBD filed another lawsuit on Wednesday, alleging the Fish and Wildlife Service is taking too long to determine whether Endangered Species Act protections are warranted for 274 other species awaiting decisions across the country — including the wolverine, found in the northern Rockies.