Lake Superior’s Record-Low Ice Cover Signals Trouble for Ecology and Economy

In an unprecedented event, Lake Superior, a colossal expanse of blue this week, unveils a scene that is both mesmerizing and alarming.

With no otherworldly ice shards smashed against the shore or colorful fish houses decorating stretches of white, the lake stands as a testament to an evolving climate.

A Historical Low

The Great Lakes have crossed a threshold. At about 2%, the amount of ice on Lake Superior is recorded as the lowest in history.

This phenomenon isn't isolated; it mirrors a trend evident across all the Great Lakes. Residents who live by the sands pit remember with nostalgia the lunar landscape that Park Point beach was known for during this time of year.

They used to love walking on the ice and seeing the different formations. It was like being on another planet. Now it's just water and sand. They feel sad.

According to the National Oceanic and Atmospheric Administration (NOAA), the average ice cover for Lake Superior in February is about 40%. The lowest it has ever been was 9.5% in 2012. This year, it has plummeted to a new low of 1.8%.

The lack of ice is not only a visual change, but also a physical one. Ice acts as a barrier that prevents evaporation and heat loss from the lake. Without it, the lake loses more water and cools down slower, affecting its temperature, water level, and ecosystem.

Lake Superior is not just warming; it's warming faster than its surroundings. A faculty member at the Large Lakes Observatory at the University of Minnesota, Duluth, found that summer surface water temperature increased faster than the change in air temperature.

This rapid warming has implications for the lake's circulation and mixing patterns, which are crucial for oxygen and nutrient distribution.

It also affects the timing and duration of the seasonal thermocline, a layer of water that separates the warmer surface from the colder depths. The thermocline acts as a barrier for many fish species, limiting their habitat and food sources.

The Implications and Portents

As enchanting as an iceless Lake Superior may appear, it raises pertinent questions about climate change and its impacts on natural ecosystems. Residents and environmentalists alike are prompted to ponder - what does an iceless Lake Superior portend?

One of the possible consequences is the disruption of the lake's food web. Ice provides a habitat for algae, which are the primary producers of the lake.

Algae feed zooplankton, which in turn feed fish and other aquatic animals. Without ice, algae production may decline, affecting the entire chain of life.

A study by researchers at the University of Michigan found that the decline of ice cover in Lake Superior has led to a decrease in the abundance and diversity of diatoms, a type of algae that forms the base of the food web.

This has cascading effects on the rest of the food web, reducing the growth and survival of fish such as lake trout and whitefish.

Whitefish is the main fish species in Anishinaabe culture, and it is also important for commercial and recreational fisheries.

The lead fisheries biologist for the Sault Sainte Marie Tribe of the Chippewa Indians is greatly concerned about the whitefish population in Lake Superior as well as in Lakes Michigan and Huron.

He says that whitefish is the fish species that is most important throughout their creation history. He worries that if the projections are what they are appearing for climate change, they may be going into a sort of bad situation with the ability for whitefish eggs or even lake trout eggs to be able to survive.

Another consequence is the alteration of the lake's weather patterns. Ice moderates the lake's effect on the surrounding air, creating milder winters and cooler summers. Without ice, the lake may generate more lake-effect snow in the winter and more thunderstorms in the summer, increasing the risk of floods and erosion.

A water resources engineer with Environment and Climate Change Canada says that the lake's influence on the regional climate may change as the ice cover declines.

He says that maybe what used to happen in March might now be happening in February or January. He says that the timing of things might change a little bit.

A third consequence is the threat to the lake's cultural and recreational value. Ice offers opportunities for fishing, skating, snowmobiling, and other winter activities that attract tourists and locals alike.

Without ice, these activities may become less feasible or enjoyable, affecting the lake's economic and social benefits.

Ice also has a spiritual and historical significance for many people, especially the Indigenous communities that live around the lake.

The omiwatari, the ice ridge that forms on Lake Suwa in Japan, is an example of how ice connects people with nature and tradition.

The omiwatari has been celebrated and recorded by Shinto priests since 1397, but it has become increasingly rare in recent years due to the warming of the lake.

These consequences are not inevitable, but they are plausible. They are also not irreversible, but they are preventable. The fate of Lake Superior, and the Great Lakes as a whole, depends on the actions of humans, who have the power to mitigate or exacerbate climate change.