Minnesotans are witnessing a chilling trend as lake ice diminishes over time. Jeff Sundin, a Grand Rapids fishing guide with 40 years of experience, reports that recent years have seen notably delayed cold weather in the fall. His anecdotal evidence is supported by the Minnesota Pollution Control Agency, as they have documented an average loss of ice coverage on Minnesota lakes by approximately 10 to 14 days across the past five decades. Duluth News Tribune relayed that the ice-in dates are occurring roughly nine days later, and ice-out dates have advanced by four to five days earlier than in past years.
The primary culprit behind the shrinking ice seasons, according to climate experts, is the rapidly warming Minnesota winters. Pete Boulay, a climatologist with the Minnesota Department of Natural Resources, emphasized to Duluth News Tribune the significant rise in overnight minimum temperatures during winter, which fails to support the formation of lake ice. Duluth itself has experienced a winter temperature increase of 6.4 degrees from 1970 to 2020.
Despite the observable impact of climate change on ice coverage, one area that has yet to be extensively studied is the aftermath of these shorter ice durations. Twin Cities reported on a research review in Science co-authored by Ted Ozersky, an associate biology professor at the University of Minnesota-Duluth who notes that the lack of research may be due to several factors. A dearth of winter lake studies can be attributed to inadequate ice-safety training for researchers, seasonally oriented research schedules, and a historical disinterest assumed from the absence of winter-focused studies in scientific literature.
The review, which Ozersky co-authored, encapsulates several key findings related to the ecological implications of the loss of seasonal ice. Among them is the prediction that fewer winter kills in smaller lakes could disrupt existing ecosystems by allowing fish to flourish in once-fishless lakes. Additionally, less ice coverage translates to an increase in lake-effect snow and rain for regions downwind of larger bodies of water. Ozersky foresees the involvement of social scientists in future research to better understand how communities are perceiving and experiencing these changes. Sundin, capturing a sentiment of generational change, told Twin Cities about his intention to "track and remember the stories to tell our grandkids."
