Study: Melting glaciers threaten rare insect that feeds trout

BOZEMAN, Mont., Dec. 8 (UPI) -- The average day hiker in Glacier National Park is unlikely to notice the dwindling stonefly population in Montana. But trout are. The western glacier stonefly is one of the few flies to hatch throughout the winter, even on the coldest of days.

But the rare aquatic insect is under threat, researchers at the U.S. Geological Survey say, as a result of loss of glacial ice. USGS biologists teamed up with scientists from Bucknell University and the University of Montana to study the imperiled insect, concluding that the bug's future is severely jeopardized by ongoing glacial melting and the rising temperatures of local streams.

Their findings were published last week in the journal Freshwater Science.

"Many aquatic species are considered vulnerable to climate change because they are cold water dependent and confined to mountaintop streams immediately below melting glaciers and permanent snowfields," Joe Giersch, project leader and USGS scientist, said in a recent press release. "Few studies have documented changes in distributions associated with temperature warming and glacial recession, and this is the first to do so for an aquatic species in the Rockies."

The researchers say they found evidence that as temperatures have warmed and glacial ice has disappeared, more and more stoneflies have relocated to higher elevations and colder environs upstream. But with global warming models predicting the end of the glaciers in Glacier National Park by 2030, that option may soon be gone.

"Soon there will be nowhere left for the stonefly to go," said Giersch.