Over the past century, ice cover in many Wisconsin lakes has declined by an average of one month during winter. Yet the consequences of this pronounced shift are unknown. The research of Hilary Dugan, an NE CASC principal investigator, aims to unravel this mystery by exploring the implications of ice loss for the health of Wisconsin lakes and the aquatic life inside them. Dugan’s work, which was recently featured on Wisconsin Public Radio, counters the conventional wisdom that little of consequence occurs in lakes during the winter.
“The long-held status quo is that there’s not a lot happening, it’s not important in terms of the annual, the big picture,” says Dugan, an assistant professor in the University of Wisconsin-Madison Center for Limnology. “[The old idea is] we can ignore winter, because things definitely slow down.”
But as Wisconsin winters have become shorter and more variable--a trend climate scientists expect to continue for the foreseeable future--things may not be slowing down as much as they once did. Moreover, as the climate continues to warm, the once unimaginable scenario of Wisconsin winters unaccompanied by frozen lakes may become a reality. For Dugan, this possibility raises fundamental questions about how lakes are impacted by climate change and what its ripple effects might be. To begin investigating this issue, she and her research team use snow plows and snow blowers to keep acres of lake surface free of snow throughout the winter. Preventing snow accumulation on lakes will, Dugan says, reasonably simulate the ice-free lakes in Wisconsin's future by allowing sunlight to penetrate through the food web. More light probably means more winter algae growth, which in turn may set off a chain reaction that could alter the nutrient, greenhouse gas, and aquatic life composition of many Wisconsin lakes. Dugan's experiments thus serve as a key to understanding how Wisconsin's lakes might evolve in the coming decades and may provide the foundation for a plan to help the species that inhabit them adapt to the impacts of climate change.