Climate change is causing freshwater lakes around the world to freeze for shorter periods of time, which has significant implications for human safety, water quality, biodiversity, and global nutrient cycles. Led by Carnegie Science’s Stephanie Hampton, an international team of researchers from the United States, Canada, and Sweden has conducted a review that serves as a call-to-action for wintertime freshwater ecology research. The study, published in Science, highlights the drastic reduction in the duration of lake ice over the past 25 years, with melting starting at least a month earlier than in previous centuries.
The decrease in ice duration has major implications for communities that rely on freshwater lakes for drinking water, recreation, fishing, transportation, and cultural identity. Hampton, a freshwater ecologist with extensive experience studying Lake Baikal in Siberia, emphasizes the need for a global effort to understand the risks posed by ice loss. The team’s analysis outlines the ecological harm caused by ice loss, from impacts on individual lakes to disruptions in global nutrient cycles.
Shorter ice duration and warmer temperatures can lead to water quality impairments in lakes, such as toxic blooms of cyanobacteria that threaten fish and human health. Changes in ice cover also affect the biodiversity of lake ecosystems, allowing invasive species to thrive while cold-water organisms suffer. Additionally, ice loss influences the global carbon cycle, with evidence suggesting that warming water releases greenhouse gases into the atmosphere.
As over a billion people live near lakes that freeze, the changes in ice duration have far-reaching effects on human communities. The researchers stress the need for further research to understand how loss of lake ice is altering the water cycle, including increased evaporation and potential impacts on snowfall and erosion. Hampton and her colleagues are advocating for a deeper understanding of the roles that lake ice plays in the health of the planet and the communities that depend on these bodies of water.
Despite decades of research on Northern Hemisphere and high-elevation lakes, wintertime lake ecology is still an emerging field. Hampton and her colleagues are at the forefront of developing safe research protocols in iced-over conditions, with protocols being created to train early career researchers. Moving forward, there is a need to invest in studying the critical roles that lake ice plays in maintaining the health of the planet. The paper’s co-authors include researchers from various institutions, further highlighting the collaborative effort needed to address the complex challenges posed by climate change on freshwater lakes.