There are a variety of ecological, economic, and social impacts that result from reduced ice cover. They range from a reduction in opportunities to ice fish to alterations in habitat availability for fish during the summer months. A warming climate in the Adirondack region is causing a shorter duration of ice cover on regional lakes each winter.

How and why lake is ice changing

Throughout the Adirondack region and across the northern hemisphere, lakes are experiencing significant reductions in lake ice cover over the past century. One of the most notable reductions in ice cover in the region is Lake Champlain. In the early 1900s, the lake consistently froze completely, whereas today, the lake freezes on average once every four years. Modeling by the national weather service suggests the lake may freeze only once every decade by 2050.¹

Smaller lakes in the Adirondack uplands still freeze completely every year but are experiencing significant declines in the duration of ice cover. Mirror Lake in the village of Lake Placid has one of the longest ice records in the country, dating back to 1903. Today's average duration of ice cover on the lake is 24 days shorter than it was in the early 1900s.² This change is being driven primarily by later ice formation.2 Monitoring of lake ice at SUNY ESF's Huntington Wildlife Forest has documented similar trends across five lakes that have been monitored since the early 1970s.³

The observations of shifts in ice cover here in the Adirondack region are reflections of broader patterns being observed across the Northern Hemisphere. The number of lakes experiencing intermittent ice cover, like Lake Champlain, is expected to increase exponentially with a warming climate. Current modeling suggests that, in the absence of significant cuts in carbon emissions, there will be a 3.8-fold increase in the number of lakes in the Northern Hemisphere that will experience intermittent ice cover (from 15,000 to 57,600 lakes).⁴

Cultural implications of changing lake ice

The most direct impact of a reduction in lake ice that most of us will feel is a change in the recreational and subsistence activities that rely on frozen lakes. Ice fishing, pond hockey, and Nordic skating are popular outdoor activities that rely wholly on safe ice on our lakes and ponds. Experiencing an expansive frozen lake or pond also provides spiritual and artistic connections to the landscape and can generate interest in natural history and resource protection. There are also ceremonial, artistic, education, and research activities that may be impacted by reduced lake ice as well.  For many people, it is hard to imagine a winter in the Adirondack region without these activities. Ice fishing, in particular, is a popular activity with a strong social and cultural identity.

Snowmobiling is a popular winter activity that relies on frozen lakes and ponds and is a major winter industry in many of our local communities. One study looking at the impact of climate change on winter recreational activities in the northeastern US estimates the snowmobiling season will decline by 53% by the end of the century under a low emission scenario.⁵ Coupled with reduced duration of ice cover we are likely to see significant changes in winter recreational opportunities in the Adirondack region. Furthermore, it is likely that we will also see a decline in ice thickness, putting winter recreationists that do venture onto frozen lakes and ponds at greater risk of serious injury or death.

In other parts of the world, lake ice plays a significant role in ceremonial and religious activities. For example, in 1443, Shinto priests began celebrating the appearance of an ice ridge on Lake Suwa, referred to as omiwatari. Omiwatari is believed to be formed by the god Takeminakata as he crosses the lake to visit the god Tasakatome at her shrine across the lake. The appearance of omiwatari marks the beginning of a purification period during which monks hang sacred ropes at the entrances to their houses and purify their homes, bodies, and minds. Omiwatari is occurring less frequently today, resulting in alterations in the religious practice of the Shinto priests.⁶

Ecological implications of changing lake ice

Alterations in the timing and duration of ice cover on lakes can result in significant changes in lakes' physical, chemical, and biological processes. In many cases, the changes associated with changes in ice cover have implications beyond the winter season, altering lake ecology throughout the entire year.⁷ One example is a shift in the timing and duration of thermal stratification, which is the seasonal layering of lake temperature. In some cases, earlier ice-off can result in a prolonged period of spring mixing. And later ice-on can result in prolonged thermal stratification.

Prolonged spring mixing is believed to be one driver for significant impacts on phytoplankton communities within lakes. These organisms are an important source of food for aquatic life and serve as the base of the aquatic foodweb. Lakes across the northern hemisphere are seeing a rise in the abundance of the diatom Discostella stelligera. In some cases, this species has gone from relatively rare to the dominant species within the planktonic (open water) diatom community.⁸ Diatoms are one of the most abundant groups of phytoplankton in lakes and the full implications of dramatic shifts in their populations are yet to be fully understood. 

On the other hand, prolonged thermal stratification directly affects cool and cold-water fish, most notably lake trout (Salvelinus namaycush). When lakes are thermally stratified in the summer, the waters at the lake's surface are too warm for these fish, so they seek refuge in the dark, cold waters near the lake bottom. During periods of stratification, these waters are cut off from exchanging oxygen with the atmosphere. As a result, the longer the lake remains stratified, the lower the oxygen levels become. This is because the fish and other organisms, such as bacteria, are using up the oxygen in the water. Eventually, the fish may be squeezed into a narrow band of water where they are exposed to either the stress of low oxygen or high water temperatures. The outlook for lake trout in the Adirondacks doesn't look particularly good.

Other ecological implications of reduced ice cover for Adirondack lakes include changes in light availability and nutrient cycling, shifts in the growing season for aquatic plants, and mismatches between the emergence of different organisms after winter dormancy.⁷⁸ All of these changes have the potential to fundamentally impact our lakes and modify how we interact with them. 

AWI's efforts to study lake ice

AWI recognizes the cultural and ecological importance of studying changes in Adirondack lake ice. Since 2015, we've been tracking the ice on Mirror Lake along with our partners at the Ausable River Association. And we've been keeping track of ice observations made by others on Adirondack lakes (Upper Saranac Lake, Lower St. Regis Lake, and others). While the duration of ice cover has been tracked historically, in 2020, we started monitoring ice thickness which is directly related to ice safety and the availability of light to drive lake productivity. Ice in/out and ice thickness data are helping us understand some of the drivers of the changes we are seeing on these lakes and serve as historic records as we continue to monitor climate change impacts to our region.

If you’d like to contribute to this important work, join the Lake Ice Observation Network, a crowdsourced community science project to track lake ice coverage and thickness. A simple web form allows you to record the extent of ice cover and the ice thickness and snow depth on lakes and ponds in your area. Using your smartphone, the form automatically records your location, and the data is then shared publicly through a web map. You are joining dozens, hundreds, or possibly thousands of people who are contributing to this project. The Lake Ice Observation Network is deepening our understanding of how ice conditions change over time. You can learn more by clicking the button below.

Changes in lake ice are just one-way climate change is impacting Adirondack lakes. Understanding these cultural and ecological changes is essential to address this pressing challenge. With your help, we can build greater climate resilience in our communities and across our landscape.

1. Lake Champlain Basin Program. 2021. 2021 Lake Champlain State of the Lake and Ecosystem Indicators Report. Lake Champlain Basin Program, Grand Isle, VT.

2. Wiltse B.W & Stager J.C. 2022. Data from: Mirror Lake, NY Ice Record [dataset]. Research Gate. http://dx.doi.org/10.13140/RG.2.2.32575.20642

3. Beier C.M., Stella J.C., Dovčiak M., & McNulty S.A. 2012. Local climatic drivers of changes in phenology at a boreal-temperate ecotone in eastern North America. Climate Change, 115: 399-417.

4. Sharma et al. 2019. Widespread loss of lake ice around the Northern Hemisphere in a warming world. Nature Climate Change; https://doi.org/10.1038/s41558-018-0393-5

5. Scott D., Dawson J., & Jones B. 2008. Climate change vulnerability of the US Northeast winter recreation – tourism sector. Mitigation and Adaptation Strategies for Global Change, 13:577-596.

6. Knoll et al. 2019. Consequences of lake and river ice loss on cultural ecosystem services. Limnology and Oceanography Letters, 4:119-131.

7. Dugan H.A. 2021. A comparison of ecological memory of lake ice-off in eight north-temperate lakes. JGR Biogeosciences, 126(6): e2020JG006232

8. Wiltse B.W., Mushet G.R., Paterson A.M., & Cumming B.F. 2022. Evidence for temporally coherence increases in the abundance of small Discostella (Bacillariophyceae) species over the past 200 years among boreal lakes from the Experimental Lakes Area (Canada). Journal of Paleolimnology, https://doi.org/10.1007/s10933-021-00232-7