Scientists Race To Research Stonefly Species Threatened By Climate Change

Sep 7, 2018

Scientists know very little about a species of stonefly that can only be found in the alpine streams of the Grand Teton Mountain Range: the Lednia tetonica.

It was discovered in 2012. But as climate change slowly melts glaciers and threatens the aquatic insect's habitat, researchers are trying to learn as much as they can about the species, before it disappears.

Scott Hotaling looking for stoneflies in a stream under Skillet Glacier.
Credit Taylor Price

On a cold morning at a Grand Teton campground, three scientists prepared to do just that by packing their bags for an expedition.

Scott Hotaling, a post-doctoral scholar at Washington State University, got out of his green Subaru and said, "it's about 6 am, people are just starting to wake up and we're heading to the Skillet Glacier later today."

He's alongside Lusha Tronstad, the invertebrate zoologist at the Wyoming Natural Diversity Database at the University of Wyoming.

These two scientists and a graduate student, Taylor Price, have been visiting sites around the Tetons for over a week, collecting data of the small, brown aquatic stonefly that lives only in glacier-fed streams.

In the first leg of today's journey to Skillet Glacier, the team jumps on a boat in Jackson Lake.

Scott Hotaling and Deb Finn on the boat across Jackson Lake.
Credit Cooper McKim

For the last four years a small group of researchers, including Tronstad and Hotaling, have been racing to study the insect and the streams it lives in. The list also includes Deb Finn, Assistant Professor, Missouri State University and Joe Giersch, Aquatic Entomologist at USGS

Very little is known about what lives in these alpine streams. These scientists are the first people to really investigate what's there.

"We call ourselves the Alpine Stream Dream Team," Hotaling said, adding they call themselves stonefly evangelists too.

They think what they find could be important. With climate change heating up temperatures in the insect's habitat, the rush to learn about it pushes the stakes even higher.

"If icy stream habitat goes away, this whole world goes away and is replaced by a warmer temperature community that is different and that's a significant blow to global biodiversity," Hotaling said.

The core team researching Lednia tetonica, in order: Deb Finn, Assistant Professor, Missouri State University, Scott Hotaling, Post-Doctoral Scholar at Washington State University, Joe Giersch, Aquatic Entomologist, USGS, and Lusha Tronstad, Invertebrate Zoologist at the Wyoming Natural Diversity Database at the University of Wyoming

After the short boat ride, the scientists headed upward, on the long, trail-less hike. Hotaling explained how after today and many more days like it the team will have a huge collection of the basic natural history of the species: the insect's population density, the microbes in the water, and the how temperature changes annually.

"We need these long-term datasets to fully clarify how these changes are happening on a year-to-year basis, or decade to decade," he said.

Already, the team has uncovered nine new sites where the stonefly lives out of only 10.

After hours of bushwhacking through willows and climbing over boulders, the alpine streams came into view. This warm, cloudless spring day was accompanied by the sound of chirping crickets and rushing water. Hotaling lifted up a rock and uncovered a small brown, wriggling insect.

"Alright here's one of the stars of our alpine stream show. This is Lednia tetonica right here. See this dark, brown stonefly?" he said.

The insect clung to rocks as freezing water rushed past it. It's the size of an ant and sort of nondescript. Tronstad explained this stonefly is important to its ecosystem by dealing with big organic matter like leaves, sticks, and moss.

"And they usually shred those up and make them into smaller pieces, and other organisms can use them downstream," she said.

They're also important because, as an indicator species, it's like a canary in a coal mine. As stoneflies start going away with warming waters, that means climate change could be having other impacts on the alpine stream ecosystem. And that affects water everywhere.

"These are the headwaters of the world and so everything that happens up here, all the organisms that live or die, all the water that flows out of a glacier, it all goes into Jackson Lake down here, and it continues until it goes out into the world's oceans," Hotaling said.

He moved up and down the stream in search of 20 Lednia tetonica to study later, inserting each one into a filled clear Nalgene bottle. Further down the slope, the graduate student brushes stones from the stream collecting algae, fungi, and bacteria. Over time, her research will show how the insect's food sources could be changing with the climate.

A Lednia tetonica nymph found on a rock under Skillet Glacier.
Credit Cooper McKim

Ten feet away, Tronstad gathered data on the stream, noting how much algae is in the stonefly's habitat, what size rocks are there, pH, as well as what other insects are present to learn population density. While they still can, scientists are collecting this baseline data and will watch over the course of years as climate change transforms this world.

"And watching, waiting and collecting data every year is really the best thing we can do to figure out how this is all going to play out and end," Tronstad said.

The next morning, after a steep downward hike from Skillet Glacier, a new question around the stoneflies gets addressed: can the species withstand warmer temperatures?

Some scientists are working with the UW National Park Service lab in the Teton's. They've already learned it can withstand higher temperatures, though not well. Hotaling said it's one more question they'll have to take on and that's no problem.

"We'll be back, that's the only constant," he said, "We will show up next year."

There's more to learn about this tiny, brown alpine species... and it could have bigger implications than the tiny stonefly itself.