Gazing over a frozen lake, it’s hard to imagine a lush forest of green plants, especially under your boots, through the snow, and under a foot or more of solid ice. But believe it – there is a thriving ecosystem down there, even though its residents may be a bit more lethargic than last time you saw them.
In an effort to understand what our aquatic plant communities look like beneath the ice, and which species are toughing it out during the long, dark winter, I have been working with a couple of fellow botanists to peer into this mysterious world. Bringing along a bunch of homemade equipment, some specialized camera gear, a lot of warm clothing, and some equally crazy colleagues, I set out to find some answers.
On a few weekends per year since 2012, we have visited fourteen lakes in Central and Northern Wisconsin, marking a few of the sites so that we could repeatedly visit them and watch how they change through the winter season. As of our last adventure on March 1st, 2015, we compiled a list of 30 species that are persisting as apparently healthy, green plants under the ice. We’ve also been delighted to see an abundance of animal life living in these miniature forests, especially caddisflies, large zooplankton like Daphnia and copepods, and fishes such as sculpins, bluegills, and bluntnose minnows. Beds of green plants appear to be serving as gathering places for animals at a time when other areas of the lakes are desolate by comparison. Old Man Winter brings us lakes that appear lifeless and frozen in time, but rest assured they are swimming with life! We have video of all that life that you can check out on the UWEX Lakes Youtube channel.
What started out as a one-day trip to a couple of lakes has turned into a Sunday tradition to explore additional lakes and seek out individual plant species. Each spring, we’re always excited to see which of our leafy friends powered through to see the light – the light of springtime, that is.
Paul Skawinski is the Statewide Coordinator of the Citizen Lake Monitoring Network, and teaches Aquatic Plant Biology at UW-Stevens Point. He is also the author of Aquatic Plants of the Upper Midwest.