Rare Glacier Stoneflies Gain Federal Protection

Two obscure stoneflies found exclusively in Glacier National Park’s high alpine streams were listed as threatened under the Endangered Species Act

Two rare aquatic insects that live exclusively in the high alpine streams of Glacier National Park and its mountainous surroundings have gained federal protection under the Endangered Species Act, becoming the first listed species to face extinction solely due to climate change.

The U.S. Fish and Wildlife Service (FWS) announced last week it has determined that two species of stonefly — the meltwater lednian stonefly, or Lednia tumana, which lives in cold-water streams fed by Glacier Park’s melting namesake, and the western glacier stonefly, or Zapada glacier, which occupies similar habitat extending into adjacent wilderness areas and Grand Teton National Park — warrant protection through listing because the glaciers supplying their cold-water refuges are projected to disappear by 2030.

“Most remaining glaciers and snowfields in Glacier National Park, one of the primary locations where these species are found, are predicted to completely melt by 2030,” according to the federal rule.

“As a result of this anticipated loss of habitat, only a few refugia streams and springs are expected to persist in the long term,” the rule continues. “Recolonization of intermittent habitats where known occurrences of either species are extirpated is not anticipated, given the poor dispersal abilities of similar stonefly species. Threats to meltwater lednian stonefly and western glacier stonefly habitat are currently occurring rangewide, are based on empirical evidence of past and current glacial melting, and are expected to continue into the foreseeable future.”

To determine the listing, FWS worked closely with partners including the U.S. Geological Survey (USGS), the National Park Service (NPS), the U.S. Forest Service (USFS), and the Confederated Salish and Kootenai Tribes (CSKT) to assess the best available science before making the decision, which has been years in the making.

For more than a decade, biologists, federal land managers and conservation organizations have been closely tracking the fate of the insects, knowing they serve as a harbinger of other stressors related to climate change.

“This is the only species to my knowledge that has been listed under the Endangered Species Act exclusively because of climate -induced threats, and in this case climate-induced glacier and snow loss,” Clint Muhlfeld, an aquatic ecologist at the USGS Northern Rockies Science Center in Glacier Park, which provided much of the scientific basis to warrant the listing, said. “These bugs are icons of climate change on a global scale. They are the polar bears of Glacier National Park.”

It’s uncertain what measures management agencies like FWS can or will take to preserve the insects, and the federal listing stopped short of designating critical habitat protections, reasoning that the species occupy areas already furnished with protection by the National Park Service and under the Wilderness Act.

However, given the close ties linking the future persistence of the stoneflies to their dependence on diminishing glaciers, resource managers said they could play a key educational role informing future climate-related policy.

“Given that these species live in remote places that are already protected there is nothing in a management plan to direct us at a local level on how we can help it along,” FWS Listing and Recovery Biologist Jim Boyd said. “But there’s always that educational value of raising awareness of what’s going on in these ecosystems and how imperiled they are given the changing climate.”

Taylor Jones, an endangered species advocate for WildEarth Guardians, a conservation group that petitioned the federal government for the species’ listing in 2007, said it’s her hope that the insects could one day serve as key players in shaping policies to regulate carbon emissions and other climate stressors, perhaps triggering a whole line of management steps to curb climate change.

“I would like to see our federal agencies as a whole address the climate crisis in a constructive way, which they have not done,” Jones said. “What we really need is for our federal government to be coming up with holistic climate solutions.”

Still, adding the stoneflies to the endangered species list might help preserve other native fauna, which would be a step toward tackling the bigger problem of global warming, according to Muhlfeld.

“In terms of local management and conservation, there is very little if anything that local managers can do. This is a global phenomenon,” Muhlfeld said. “Ultimately, the most beneficial tool for conserving alpine stream biodiversity may rest in reducing human stressors such as global carbon emissions that contribute to global warming, glacial decline and the loss of alpine habitat.”

Since 1900 the mean annual temperature in Glacier National Park has increased by about 2.5 degrees Fahrenheit – nearly two times the global mean temperature increase. Of the estimated 150 glaciers in the park in 1850, only 25 remain, and they continue to shrink.

Joe Giersch, a USGS researcher who for the past decade has ventured into Glacier Park’s remote alpine environs to study the insects, said additional research is needed to understand other cold-water dependent species occupying rarefied ecosystems.

“More research is urgently needed to assess the extent to which climate change threatens the persistence of [the western glacier stonefly] and other endemic mountaintop invertebrates and communities in Glacier National Park and worldwide,” Giersch said.

Muhlfeld agreed, adding: “What we are documenting here is really a call for action.”

“We need scientists to gather more information on the biodiversity of this system. That might become another call for more action at a global scale to reduce carbon emissions,” he said. “This really highlights the role of these species as sentinels of climate change in the region. They really are the canary in the coal mine for climate-induced threats to biodiversity in mountain ecosystems.”

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