More than a dozen scientific crews from US and Canadian universities and government agencies are venturing onto the frozen Great Lakes to help unravel the lakes' winter secrets. The field studies over the past few weeks—a collective effort known as the "Winter Grab"—are intended to boost knowledge of what happens in the five lakes when they're covered partially or completely with ice, per the AP. Lake scientists long have considered winter a season when aquatic activity slows, and most do their field studies at other times of year. But researchers now think more is going on in the bitter depths than previously believed, including activity influenced by climate change.
"All of these different components of the ecosystem ... we always measured during the summertime, but we really don't know what's taking place out there in the wintertime at all," said Don Uzarski, director of Central Michigan University's Institute for Great Lakes Research. "You can't take half the puzzle and figure out what it looks like. You have to put the whole thing together." Among other things, the mission will produce data on light penetration through the ice. "Light is driving photosynthesis, which is the energy for the entire ecosystem," Uzarski said. Scientists also will analyze the samples for organic matter, particularly tiny plant and animal plankton at the base of aquatic food chains.
The Winter Grab was organized with a sense of urgency: Great Lakes ice cover has been shrinking since the 1970s. Some experts say it may become increasingly rare as the climate heats up. That could have many ripple effects beyond devastating the ice fishing industry, Uzarski said. Without ice, there's more winter evaporation. If that lost water isn't replaced by rain or snow, lake levels drop—with potential implications for wetlands, nutrient concentrations, and fish. "It is all connected," Uzarski said.
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