Climate Change Leads Aquatic Species To ESA Listing

Nov 22, 2019

Meltwater lednian stonefly, right: Western glacier stonefly.
Credit Joe Giersch

The U.S. Fish and Wildlife Service (FWS) pointed to impacts from climate change in its November 21 listing of two stonefly species. The meltwater lednian and the western glacier stonefly were listed as threatened under the Endangered Species Act. Both primarily inhabit Glacier National Park, but the western glacier stonefly also has populations in Grand Teton National Park.

The final ruling explains the invertebrates' habitats are facing serious threats as glaciers quickly disappear and increased drought is thought to reduce critical water sources.

"Once the glaciers and snowfields completely melt, meltwater lednian stoneflies and western glacier stoneflies will have no physical habitat left to which to migrate upstream," the ruling explains.

It goes on to explain drought and glacier recession are moving so quickly that available habitat for the two species in Glacier National Park could be reduced by 81 per cent by 2030.

Scott Hotaling, a postdoctoral researcher at Washington State University, was part of the team that discovered the western glacier stonefly had populations in Wyoming as well as Montana. According to FWS' final ruling, the western glacier stonefly has populations in only 16 streams and has a smaller population than the meltwater lednian.

Hotaling said the aquatic fly serves a lot of different ecosystem functions, "from breaking down organic matter so that it can be taken up and used by other organisms. They are a food source for many things, they feed on other things. They're just, they’re a link in the in the ecological chain."

He added the full impact of the species' disappearance is hard to gauge given there's still so little known about them.

The final ruling doesn't prescribe a solution. Hotaling said how to protect the species is a million-dollar question.

"Glaciers are going away and they're not something that we can put back. We can't stop polluting glaciers. It's not like we're digging them up and actively removing them. They are receding," he said.

Hotaling said this isn't just a story about a struggling species, but about the streams they live in. He said the disappearance of the glaciers and the headwaters they produce could have a substantial impact on all water sources that they feed… from a given stream to rivers to the ocean.

The western glacier stonefly is the first invertebrate species to be federally protected in Wyoming, according to Lusha Tronstad, invertebrate zoologist at the Wyoming Natural Diversity Database at the University of Wyoming.

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