The Great Lakes: A Treasure Under Threat

            Have you ever been to Lake Superior? It’s the largest freshwater lake in the world and currently holds about 10% of all of the freshwater on the planet. Lake Superior is also known to be home to 88 different fish species and is a vital part of the ecosystems of the entire Midwest region, along with the other Great Lakes. Last summer, I attended a friend’s wedding in Calumet, Michigan, which is near the coast of Lake Superior up on the Keweenaw Peninsula. During that warm week in June, the lake was absolutely stunning. Deep, clear blue water stretches as far as the eye can see, communicating the sheer scale of the wonder as cold, gentle waves wash up on rocky beaches that shine with multicolored agates, making the beach look more like a decorative pond than a natural coastline.

The pictures don't do it justice - if you get the chance to go, go. (Image Credit)

As a native Michigander, I have many personal memories from growing up near the Great Lakes, including everything from days at the beaches to experiencing the truly unique ecological biome that is the entire state of Michigan. This is a near-universal experience for anybody who grew up in this state, which is what makes the effects of climate change on this incredible area even more of a personal tragedy than they already would be.  To start, the Great Lakes are among the fastest warming bodies of water in the world. This warming puts many delicate aspects of them at risk, including shifts in seasonality and the destruction of temperature stratification, as well as the loss in winter ice cover. Additionally, certain invasive species are also threatening the biodiversity of the great lakes, which are aided by the changing climate. Finally, climate change will not just affect the natural life in the great lakes, it will also affect human interactions such as fishing and shipping.

Temperature stratification is a phenomenon where distinct temperature layers will form in bodies of water due to its temperature and density gradient. When the season changes from summer to fall and the temperatures drop, the surface water cools down and begins mixing with the water below it. The resulting up and down currents serve to bring nutrients on the lakebed up near the surface and oxygen down to the bottom, sustaining life at every depth. Because of warming winters, this mixing may not be as effective as it once was, which leads to a loss in biodiversity in the body of water. (page 30) Additionally, increased rainfall from climate-related storms will increase runoff from agricultural fields, and along with the decreased mixing of layers, can lead to destructive toxic algal blooms. These events are commonly seen in Lake Erie and have led to nearly $71 million dollars in damages in 2011 alone and are predicted to cost Canada $5.3 billion dollars in damages over the next 30 years.

Climate change also affects the spread of invasive species into the great lakes, which also damages the biodiversity of the region. Alterations of water conditions such as temperature and oxygen saturation lead to the movement of species further northward, as they search for a comfortable place to live and thrive within their niche. (page 31) This movement also aids the invasion of well-known non-native species such as the zebra mussel, sea lamprey, and Asian carp.

The effects of climate change on the Great Lakes will also directly affect human populations as well through commercial businesses such as fishing and shipping as well as through water use. (Page 43) Changes in the water levels of the lakes could in the future affect the ability of ships to move through rivers to coastal Michigan cities. Water level decreases due to drought will be especially challenging for this problem. Lakes Michigan and Huron are especially vulnerable to water level changes, and it has been predicted that water level loss will directly increase shipping costs. In addition to shipping costs, the aforementioned algal blooms also lead to a loss in available drinking water for people living on the coasts of the lakes. For instance, in 2014 the city of Toledo issued a ‘do not drink’ order for its city water as a toxic algal bloom grew on Lake Erie. This led to the water for nearly half a million people being shut off in Ohio and southern Michigan for days. People living near these areas have adapted to the times by altering farming practices and tweaking other aspects of life, but the process has been time-consuming and incredibly expensive, costing about 1 billion dollars in the years since.

(Image Credit)

The Great Lakes are more than just large bodies of water. They serve as vital ecosystems, cultural landmarks, and important resources for everyone living near them. The challenges posed by climate change on these waters demand urgent attention. Protecting these natural wonders isn’t just an environmental obligation but it embodies a profound commitment to the protection of our beautiful state. Efforts to prevent and mitigate the damage caused by climate change need to occur immediately, if we can ever hope to save our world.