Several decades of data have shown that average winter air temperature is a good predictor of average winter ice cover. On Lake Erie, an increase of just 2℃ predicts a drop in ice over from 60% to zero. And, as it turns out, that doesn't just just reduce ice fishing, it may reduce fish.
Corbin Hilling, PhD, with the USGS Lake Erie Biological field station has been working to understand how environmental conditions can influence fish reproductive success. He became interested in how underwater conditions differ across years, specifically on mid-lake spawning reefs where coldwater fish eggs develop over the winter. When reviewing prior research, he noticed it suggests that more fish eggs may survive during high ice years.
Since the highest point on these reefs often rises to just a few feet below the surface of the lake, he wondered if ice was important in protecting fish larvae from being swept away or buried in sediment due to large waves during winter storms. Hilling recruited researchers to help test his hypothesis, including Cary Troy, PhD, a civil engineer at Purdue, and myself, a limnologist at UMD's Large Lakes Observatory. Together, we prepared a proposal that resulted in the Midwest Climate Adaptation Science Center, a USGS program hosted by the University of Minnesota, awarding us funding for a two-year field experiment.
The data collection phase of the experiment began in December 2024 when we deployed three moorings on and around Niagara Reef in western Lake Erie to measure wave height, ice thickness, currents, turbulence, and sediment resuspension. The results of this data could mean a breakthrough in understanding not just changing winter ice conditions, but how those conditions impact the species we depend on for Friday fish frys and year-round recreation. We know that winter conditions can be very turbulent when the lake is ice free, and very calm when it's frozen over, but we have yet to actually measure these conditions right where the fish and fish eggs spend their winters.
The results from this experiment will not only help us understand processes at natural mid-lake reefs, but can also be applied to improving the design of artificial reefs. In the winter of 2025-2026, we hope to deploy our moorings on an artificial reef in Lake Erie to see how conditions differ. Applying this research towards successful climate adaptation will hopefully mean that whitefish and cisco won't disappear with the ice.
