In accordance with a settlement agreement with the Center for Biological Diversity, the U.S. Fish and Wildlife Service today proposed Endangered Species Act protection for the western glacier stonefly. The agency also proposed protection for the meltwater lednian stonefly. Both stoneflies are found in streams formed by glacial meltwater in and around Glacier National Park and are immediately threatened with extinction by global warming.
“As go the glaciers of Glacier National Park, so go these two unique stoneflies,” said Noah Greenwald, endangered species director at the Center. “Global warming is changing the face of the planet before our eyes, and, like these two insects, many species are seeing their habitats disappear.”
Dependent on extremely cold glacial water for their survival, the two stoneflies are limited to streams formed by melting glaciers, snowfields and alpine springs. These habitats have already declined and are expected to decline further. 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. Only 25 of the estimated 150 glaciers in the park in 1850 remain, and they continue to shrink. The park’s glaciers are predicted to disappear as early as 2030 as a result of climate change.
“These two stoneflies have something to tell us,” said Greenwald. “Without efforts to curb our emissions, all the glaciers in Glacier National Park will certainly disappear.”
Until recently the western glacier stonefly was known from only four small streams in Glacier National Park. In August the Service received information that there may be one population in the Absaroka-Beartooth Wilderness in southwest Montana and three populations in Grand Teton National Park. There are 58 populations of the meltwater lednian stonefly, all in Glacier National Park or surrounding wilderness areas.
The Center petitioned for the western glacier stonefly with the Xerces Society for Invertebrate Conservation in 2010 and in 2015 reached a settlement agreement with the Service requiring the 12-month finding made today. Wildearth Guardians petitioned for the meltwater lednian stonefly in 2007.
Stoneflies are excellent indicators of the health of their freshwater habitats. Extremely sensitive to changes in water quality, they are among the first organisms to disappear from degraded rivers and streams. They play a significant role in many aquatic ecosystems, decomposing leaves and other organic material and forming the base of the food chain.
Fly fishers have long recognized the important role stoneflies play in providing nutrients for fish. Despite their importance these insects are among the most imperiled groups of animals in North America: More than 40 percent of all stoneflies are vulnerable to extinction because they are especially sensitive to pollution.