Winter bug "MAY" offer climate clues

By Elmer Beauregard

Saw this article in the Startribune I thought it would be a good exercise to highlight all the times WOULD and MAY were used in this article. Plus, I highlighted a few other words as well.

A flying insect that thrives in midwinter MIGHT seem like a creature from a frightening fictional Minnesota.

But Diamesa mendotae, a cold-hardy but delicate insect also known as a midge, is very real and MAY provide a measure of how the state's climate is warming, and what effect that MIGHT have.

Researchers from the University of Minnesota are working to understand more about the relationship between these unusual freeze-resistant insects and the fish that eat them in streams in the southeastern part of the state. The three-year project is primarily about brown trout, a popular target for anglers. "We're THINKING that a changing climate and increasing air temperatures will affect water temperatures, and that COULD reduce [fish] populations," said entomology professor Len Ferrington, principal investigator on the project.

The midges are also high in calories and nutrients -- "like pecan pie" for trout, Ferrington said. But their cold-hardiness is balanced by an intolerance for warmth. An increase of as little as 1.8 degrees in the average water temperature in a stream COULD wipe out an entire winter reproductive cycle for them, Mazack said. That COULD mean less food for trout during winter, or at least less nutritious food in the form of other bugs.

Lori Krider, another graduate assistant in the Water Resources Science program, has found that the water temperature in groundwater-fed streams rises an average of .38 degrees for every 1 degree rise in air temperature. An average air temperature increase of 7.9 degrees by the end of the century, PREDICTED by ONE Intergovernmental Panel on Climate Change model, COULD produce a stream temperature increase of about 3 degrees, which would be beyond midges' threshold. That COULD alter food sources and habitat for trout, the researchers said.

Researchers on the project, funded by a $300,000 GRANT from the Legislature, work in a rugged laboratory. Last week, three graduate students and a DNR fisheries specialist waded into Cold Spring Brook, just outside Zumbro Falls, to collect bug samples, then probed the stream with a long-handled, electrically charged device that shocked fish to the surface.

The team will visit 12 streams several times during each of the project's three years. On return visits, as many as 40 percent of the fish they net MIGHT be ones they've caught before, giving them opportunities to track fish growth.

"It's been KIND OF eye-opening to see how much food is in some of these fishes' stomachs," said Will French, a conservation biology graduate research assistant. "They're feeding and growing in the winter -- quite a bit, actually."

French said his interest is in how well fish are faring in the winter in any one stream compared to others. Differences COULD lead to changes in how streams are managed; researchers in a separate part of the project are examining the banks, curves, bottoms and other structural elements of streams and how they MIGHT be change as well.

Indeed, increasing warmth in the air, groundwater and streams COULD be slowed by more green buffers along streams, as well as shady plants and trees above them, Ferrington said. But for now, the POTENTIAL problems of a warming climate are being examined in the cold.