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The Great Lakes from space
The Great Lakes from space

Great Lakes Areas of Concern are designated geographic areas within the Great Lakes Basin that show severe environmental degradation. There are a total of 43 areas of concern within the Great Lakes, 26 being in the United States, 17 in Canada, with five shared by the two countries.

The Great Lakes, the largest system of fresh water lakes in the world, are shared by the United States and Canada. They make up 95% of the surface freshwater in the contiguous United States and have 10,000 miles of coastline (including connecting channels, mainland and islands)—more than the contiguous United States' Pacific and Atlantic coastlines combined. The lakes are a system of transport and shipping, as well as a place of recreation.

Description of an AOC

An Area of Concern must have at least "one beneficial use impairment which means that it has undergone a change in its chemical, physical, or biological integrity of a water body." These include:[1]

The Great Lakes Water Quality Agreement

President Richard Nixon and Prime Minister Pierre Trudeau at the signing ceremony for the Great Lakes Water Quality Agreement in 1972
President Richard Nixon and Prime Minister Pierre Trudeau at the signing ceremony for the Great Lakes Water Quality Agreement in 1972

The Great Lakes Water Quality Agreement between the United States and Canada more specifically defines Areas of Concern as "geographic areas that fail to meet the general or specific objectives of the agreement where such failure has caused or is likely to cause impairment of beneficial use of the area's ability to support aquatic life."[1] The U.S.-Canada Water Quality Agreement holds the committee and regulations that decide whether an area should be considered an Area of Concern. The goal of the agreement is to restore and maintain the chemical, physical and biological integrity of the Great Lakes Basin ecosystem through a concerted set of interventions that are targeted at the aforementioned Areas of Concern. Because each waterway has a unique set of characteristics that have contributed to its ecological impairment, a Remedial Action Plan has been developed to identify the causes of impairment which will be used to guide local actions that will restore the individual waterways. The goal of each Remedial Action Plan is to bring about the delisting of the waterway from the list of Areas of Concern

Since its original passage in 1972, the GLWQA has been amended multiple times to include preventative action towards current anthropogenic stressors. In particular, the latest amendment to the agreement was in 2012 where preventative measures were added to address issues that have arisen since the last amendment in 1987.[2] Furthermore, this amendment resulted in the invitation of additional organizations to participate in policy formation and remediation. Primarily run by the U.S. Environmental Protection Agency and Environment and Climate Change Canada, the Great Lakes Committee Members have added indigenous representatives and local public government organizations.[3] Thus, any form of remedial action takes into account the local communities’ perspectives. This governing body is also known as the Binational Executive Committee (BEC), which meets at least twice a year to establish priorities and review progress.[4] Under the GLWQA, various action plans have been established to target specific lakes. For example, the 2012 amendment resulted in the creation of GLWQA Nutrients Annex Subcommittee that will help target the algal bloom in Lake Erie.[5] Overall, the General Lakes Water Agreement is a dynamic piece of legislature that will continue to address ever-changing priorities and values.

Other laws and policies

The United States and Canada and the states that border the Great Lakes have all created several laws, policies, and commissions to try to keep the Great Lakes healthy and un-polluted. In 1909 the Boundary Waters Treaty was put into place to control the water quality in the Boundary Waters that border both the U.S. and Canada. They created the International Joint Commission to deal with the duties of the new treaty. With the realization of the sea lamprey explosion in the Great Lakes, the Great Lakes Fishery Commission was created to control the situation. In 1994 the Ecosystem Charter for the Great Lakes- St. Lawrence Basin was suggested as a good faith agreement. This was an agreement to use the ecosystem as a method of management for the Great Lakes. The Air Quality Agreement was put into place to help protect the health of not only the ecosystems of the Great Lakes but the citizens who live around them as well. It limits the amount of toxic chemicals that are given off. Another policy that was put into place in response to the toxic chemicals in the area of the Great Lakes occurred in 1997. The Great Lakes Binational Toxics Strategy was developed to control the persistent toxic substances that bioaccumulate such as DDT, PCBs, mercury and dioxins. These toxins stay in ecosystems for long after they are exposed and they can cause serious damage to the plant and animal life."[1]


This section needs to be updated. Please update this article to reflect recent events or newly available information. (December 2018)

Invasive species

One of the major problems is the number of non-native species that are taking over the lakes. Approximately every eight months a new species enters the Great Lakes, severely disrupting the ecosystems in the area.[6] New animals or insects coming into or leaving an ecosystem can be just as damaging as pollution.

A major food source for most fish in Lake Michigan had been Diporeia shrimp that have been drastically decreased by an infestation of zebra mussels. The Diporeia shrimp have declined from over 10,000 per square meter to virtually zero on the lake bottom because of these zebra mussels. In Lake Michigan the decrease in Diporeia numbers is extreme at 94% killed over the past ten years. Its neighbor, Lake Huron is down 57% in its Diporeia population in just the past three years.[6] There are many examples of this problem in each of the Great Lakes, as well.

The Great Lakes have been damaged by more than 180 invasive and non-native species. Some of these species include the zebra mussel, quagga mussel, round goby, sea lamprey, and alewife. Invasive plants include purple loosestrife and Eurasian watermilfoil. As well as throwing off the habitats of native species and the food web of the ecosystem, invasive species also threaten human health and have a major negative impact on the Great Lakes economy by damaging fisheries, agricultural industries, and tourism.

Point-source pollution

Point-source pollution occurs when pollutants enter a waterway directly. This could be from such causes as waste being dumped into a waterway. In the past, lakes and other waterways were used as a place to dump waste because it was thought that water could dilute anything, whereas more recent studies have shown this to be extremely incorrect. After several hundreds of years of constant dumping, many waterways have become contaminated with toxic chemicals and human waste.[1]

Nonpoint-source pollution

Nonpoint source pollution is pollution that occurs when runoff from streets, lawns, farms, and other areas carries toxins, chemicals, and eroded soil into nearby lakes, rivers, and oceans causing pollution and buildup of sediment. Nonpoint source pollution is said to be the most problematic and hardest to reverse of the types of pollution because it is so hard to regulate and pinpoint where it originates. Many experts agree that nonpoint source pollution is the biggest concern facing the Great Lakes. With the increase of urbanization, a toll has been taken on the lakes in these areas. Lakes that once had stable ecosystems with the appropriate amount of plant life are now full of massive amounts of plants and algae that have been fed by excess fertilizer from lawns and farms, killing off many species of fish and other water life.[1]

Atmospheric pollution

Atmospheric pollution is pollution that falls from the sky and comes to rest back on earth in the water table and in the lakes and oceans. This air pollution usually comes from smoke and chemicals being thrown into the air from smoke stacks. One of the most troubling facts about atmospheric pollution is that it usually falls hundreds of miles away from its source and therefore is difficult to track and locate, but it is a major contributor to the pollution of not only the Great Lakes but all over the world. Pollution from one country can be hurting another. The best-known type of atmospheric pollution is acid rain. Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the atmosphere. These substances rise very high into the air, they can then mix with and react with water, oxygen, and other chemicals to create pollutants known as acid rain. The effects of acid rain are mostly seen in aquatic ecosystems. As the rain flows through the soil, the acidic water can drain away aluminum from the soil and them flow into streams and lakes. As more acid is released into the environment, more aluminum is also released. There are some plants and animals that are able to tolerate acid rain and moderate amounts of aluminum, but others are not as tolerant and will start to die off as the pH decreases. One of the biggest contributors to acid rain is the burning of coal and fossil fuels.[1]

List of AOCs

Lake Superior

Lake Erie


Lake Michigan

Lake Huron


Lake Ontario

Connecting channels


See also


  1. ^ a b c d e f "Great Lakes Information Network, "Areas of Concern", ''Pollution'', Wastewater and sewage, Contaminated Runoff". Retrieved 2013-07-25.
  2. ^ "About the Great Lakes Water Quality Agreement –". Retrieved 2016-11-15.
  3. ^ "Great Lakes Executive Committee Members –". Retrieved 2016-11-15.
  4. ^ "International Joint Commission - The Great Lakes Water Quality Agreement review". Retrieved 2016-11-15.
  5. ^ 05, US EPA,REG. "Recommended Binational Phosphorus Targets". Retrieved 2016-11-15.CS1 maint: numeric names: authors list (link)
  6. ^ a b Andy Buchsbaum, "Subcommittee on Water Resources and the Environment - The Impact of Aquatic Invasive Species on the Great Lakes", House Transportation and Infrastructure Committee Archived March 28, 2007, at the Wayback Machine
  7. ^ "Great Lakes Information Network, "Areas of Concern", ''AOCs''". Archived from the original on 2013-08-03. Retrieved 2013-07-25.