Climate

Melting Glaciers Threaten Rare Insect Found Only In Glacier National Park

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The rare western glacier stonefly (Zapada glacier) is native to Glacier National Park and is seeking habitat at higher elevations due to warming stream temperature and glacier loss due to climate warming.

Glacier melt is a major player in the long-term effects of climate change, contributing to sea level rise and dwindling water supplies. But it also has immediate impacts on the organisms that live near and depend on glaciers for survival, according to a new study.

The study, which is set to be published in Freshwater Science, looked at how glacier melt in Glacier National Park is impacting the western glacier stonefly, a rare species of aquatic insect that’s found only in the park. The researchers found that the stonefly’s range is shrinking due to melting glaciers and increased water temperatures of the park’s streams.

The researchers looked at six of the cold-water, glacier-fed streams in which stoneflies had previously been found to reside, and found stoneflies in only one. The researchers also found stoneflies in two new streams at higher elevations than the fly’s historic range, signalling that the flies had moved to higher, cooler streams “as water temperatures increased and glacial masses decreased,” the report stated.

That’s concerning, because Glacier National Park’s iconic glaciers are predicted to disappear by 2030, leaving the stonefly’s future uncertain. In 1850, Glacier National Park was said to be home to about 150 glaciers; in 2010, that number had dwindled to 25.

“Soon there will be nowhere left for the stonefly to go,” Joe Giersch, lead author of the paper and and U.S. Geological Survey scientist said in a statement.

The researchers write that more research is “urgently needed” to fully understand how the stonefly is reacting to climatic changes and which other stream-dwelling invertebrates might be at risk.

“There are a handful of other coldwater dependent alpine aquatic species here in Glacier that are at risk of extinction due to the loss of permanent snow and ice,” Giersch said. “Under a warming climate, the biodiversity of unique aquatic alpine species — not just in Glacier, but worldwide — is threatened, and warrants further study.”

Glacier National Park’s shrinking glaciers are just one example of climate change’s impact on the park. As Daniel B. Fagre, a USGS research ecologist, told the New York Times, Glacier is a “snow-driven ecosystem, and glaciers are just a part of that…the way the snow goes is the way our ecosystem goes.” Glacier’s winters are warming and it’s seen a tripling in days above 90 degrees since the early 1900s. This warming has major implications for animal and plant life in the park: plants that depend on snowmelt could disappear, and creatures that depend on cold water, such as the stonefly and certain fish, could also become rarer.

The stonefly’s predicament is one shared by animals and plants around the world. As the climate warms, some birds have shifted their ranges northward, and some plant ranges have shifted farther upslope. But as Giersch said, there’s likely to come a point for some species where there’s simply nowhere else left to migrate: the planet’s climate has become unsuitable for their survival, forcing them to adapt quickly to new conditions or face extinction.