Background
Lake Superior is the largest of the five Great Lakes located on the border of the United States and Canada. It is the largest freshwater lake in the world by surface area, containing 10% of all the world’s freshwater reserves. The name “Superior” derives from its size relative to the other four Great Lakes, which are known as “inferior” lakes. Its size, depth and beauty make it a popular destination for nature lovers, fishermen, kayakers and recreational boaters from around the world.
Description
Lake Superior is the westernmost of the Great Lakes and is situated between the U.S. states of Michigan and Wisconsin and the Canadian provinces of Ontario and Minnesota. It has an area of 82,414 km2 and a maximum depth of 406.9 m. Lake Superior has two large bays, the Sault Ste. Marie Bay in the east and the Thunder Bay in the west, as well as numerous islands and islets that form the boundary between the United States and Canada.
The lake’s average temperature is 5°C and its maximum surface level is 183.8 m above sea level. It is home to a variety of wildlife, including walleye, brown trout, lake trout, lake sturgeon, and lake herring.
Is Lake Superior an Inland Sea?
There has been debate over whether Lake Superior should be classified as an inland sea. Some say it does not fit the definition of a sea because it does not have a connection to an ocean. However, many scientists and others argue that the size and depth of Lake Superior are similar to the definition of a sea, and that it should be considered to be an inland sea. For example, the US Environmental Protection Agency (EPA) and the International Sea-Keepers Association both consider Lake Superior to be an inland sea.
The EPA states that an inland sea has a surface area of more than 1,000 km2, a maximum depth of more than 200 m, and a water volume of more than 1,000 km3, all of which are qualifications that Lake Superior meets. The International Sea-Keeper Association defines an inland sea as “a depository of water, having no external connection and occupying a depressed area of the earth’s surface, surrounded by higher land, so that its waters are very deep in comparison with their width.”
Benefits of Lake Superior
Lake Superior provides many benefits to the region. It is a major source of drinking water and supplies are replenished each year by precipitation, melting snow and ice and runoff from land. It also serves as a source of hydroelectric power and tourist attractions, and its fresh water is used for shipping and fishing.
The lake is also an important environmental asset and serves as a natural barrier against flooding and protects the nearby shorelines from erosion. In addition, its depth helps to regulate the temperature of the water in the Great Lakes, which helps to maintain the health and stability of the ecosystem.
Threats to Lake Superior
Like many freshwater bodies, Lake Superior faces a range of threats. Pollution, poor land management practices and invasive species are some of the biggest threats to the lake’s health and sustainability. The Canadian Lake Superior Coalition estimates that up to 70% of the lake’s shoreline is developed and much of the pollution comes from agricultural runoff, industrial and domestic wastewater, and road salt.
In addition, the lake is home to a number of invasive species, such as the sea lamprey and round goby, which out-compete native species for food and habitat. The introduction of these invasive species has had serious consequences for the native species, many of which are becoming threatened or endangered.
Consequences of Climate Change
Climate change is having a dramatic effect on Lake Superior. Warmer temperatures are causing increased evaporation, resulting in a decrease in the lake’s surface area. In fact, the surface of the lake has decreased by over 40 cm since 1980. Warmer temperatures can also lead to the growth of algae, which can cause water quality issues.
Furthermore, climate change is making the lake more acidic, which is disrupting its food web, causing some species to suffer major population losses. The cold water species, such as the lake trout, are especially vulnerable to these changes.
Conservation Efforts
Considering the environmental threats to Lake Superior, there have been many efforts to conserve and protect the lake. The U.S. EPA, along with the U.S. Fish and Wildlife Service, Canadian government and various conservation groups, has been working to reduce pollution and protect habitats.
In addition, the U.S. and Canadian governments have implemented programs to control and manage invasive species. In 2003, the two governments signed an agreement to manage the lake’s fish resources and the introduction of invasives, and since then the lake has seen an increase in native species.
Economic Implications
Lake Superior is an important economic resource for both the U.S. and Canada. This is due to its tourism and hospitality value, commercial fisheries, shipping, hydropower and mineral extraction. The lake is also an important source of food and drinking water, as well as jobs and recreational opportunities.
The value of the U.S. economy associated with the Lake Superior Basin is estimated to be over $14 billion, making the lake a significant contributor to the economy and livelihood of the region.
Human Impact on Lake Superior
Humans have had a significant impact on the ecology of Lake Superior. Overfishing, pollution, and the introduction of invasive species have all contributed to a decrease in the population of native species and disruptions to the food web.
In addition, the construction of dams, roads and other infrastructure has altered the natural flow of water and sediment, leading to changes in the lake’s chemistry and ecology. Habitat loss has also weakened or destroyed wildlife populations and has reduced the lake’s ability to absorb and process pollutants.
Environmental Programs
Due to the human-induced threats to Lake Superior, there are a number of government and non-profit efforts to protect and conserve the lake. For example, in 1985 the U.S. and Canada signed the Great Lakes Water Quality Agreement, which was designed to protect and improve the lake’s water quality.
In addition, the U.S. has established numerous programs, such as the Great Lakes Restoration Initiative, to promote the recovery of wildlife habitats, reduce polluted runoff and address toxics and other pollutants in the lake. The International Joint Commission, which provides oversight of the U.S.-Canada boundary waters, also works to coordinate the two countries’ efforts in managing the lake.
Conclusion
It is clear that Lake Superior is an important ecological and economic asset for the U.S. and Canada. Its health and sustainability are threatened by human activities, such as pollution, habitat destruction and the introduction of invasive species. Therefore, it is essential that conservation efforts are increased to protect the lake from further harm and to ensure its future health and well-being.
