Glacial stream insect may tolerate warmer waters.

01/09/2020 Source

    A study published in Global Change Biology on July 22 found that mountain stoneflies can tolerate warmer water temperatures at least temporarily. In fact, they might even be stressed in their current extremely cold environments. One of the authors said that this does not mean that global warming will be a win for mountain stoneflies.

In the study, the researchers tested the thermal tolerance levels of several species of mountain stoneflies found in the Rocky Mountains, including the Lednia tumana, which was listed under the U.S. Endangered Species Act in November 2019 due to the rapid loss of its glacial habitat. The researchers collected larval specimens of the stoneflies from streams in Glacier and Grand Teton national parks. They then subjected some of the flies to increasingly warmer water temperatures.

They found that the stoneflies that experienced warmer temperatures expressed “heat shock proteins” at the cellular level. In this study, the researchers found these same proteins were expressed not only by stoneflies exposed to heat but also by those that were held at 3 degrees Celsius (37.4 Fahrenheit), a similar temperature to their normal conditions, indicating mountain stoneflies might be stressed in their usual cold temperature environments.

Researchers said that the study's findings raise a lot of questions, including why these insects are not found in warmer waters currently.