Great Lakes Primer

A historical look at the formation, development and management of the legendary freshwater ecosystem

  • Roger Di Silvestro
  • Jun 01, 2004
The Great Lakes are the offspring of ancient glaciers that creaked and groaned out of the north during periods of global chilling, which have occurred off and on throughout the past billion years. The glaciers might tower more than a mile high, gouging the earth and pushing massive amounts of rubble ahead of them as they rolled up the earth like a carpet. The last glaciation reached its peak about 20,000 years ago. Among the hills and moraines, depressions and carvings they left behind were the basins that filled up with water to become the Great Lakes.

The French were the first Europeans to put the Great Lakes on world maps, sailing into Lake Huron’s Georgian Bay in 1615. These early explorers were so impressed with the size of Lake Huron that they called it La Mer Douce—the Sweet Sea. But following the arrival of European culture, Huron and the four other Great Lakes did not remain sweet for long.

When the French dropped anchor in the bay, the Great Lakes basin—a region in which all water flows toward the lakes—was already home to 60,000 to 117,000 American Indians who lived in scattered villages, growing corn, squash, beans and tobacco in addition to hunting and fishing. Before the end of the 17th century, the English and Dutch also were moving in, and the French had built a chain of forts along lakeshores to protect their trade in furs. Americans fought the War of 1812 in part to expand their interests into the Great Lakes region, and at war’s end succeeded in doing so.

Development has made the Great Lakes basin one of the population centers and regional industrial leaders of both the United States and Canada. The health of the lakes has paid a heavy price for this growth, besieged by deforestation, pollution and other threats.

By the mid-1800s, most of the good farmland around the lakes was settled, and roughly 1.2 million Americans and Canadians were living in the basin. Farmers stripped away local forests to create croplands, giving rise to soil erosion and the silting of streams that fed into the Great Lakes. In the mid-20th century, the toxic effects of agriculture were compounded by the development of chemical fertilizers and pesticides. Fertilizers flooded into the lakes, stimulating the growth of algae and other water plants that subsequently died and decayed, depleting the water of oxygen and causing extensive fish kills. Burgeoning pesticide use after World War II, particularly use of DDT, jeopardized wildlife, including bald eagles, mink and hawks, in the Great Lakes area.

But agriculture was not the only human endeavor chipping away at the health of the Great Lakes. The early 19th century also saw the rise of excessive and poorly managed commercial logging in the basin, leaving the landscape denuded and adding more silt and nutrients to the lakes. In some areas of the Great Lakes, forests still have not grown back.

Starting in the 1800s, ancillaries of the logging industry, such as pulp and paper mills, began adding chemical pollution to the lakes as well as dumping in sawdust, which rotted and sucked up more oxygen, killing more fish. Among the most dangerous of the chemical contaminants was mercury, which can effect the reproductive and developmental health of wildlife and humans, particularly children. Although mercury use in the paper industry was banned in the early 1970s, mercury pollution persists because of increased contamination from power plants that burn coal high in mercury.

Lake pollution has contributed to the decline of another enterprise in the basin—commercial fishing. The fishing industry began expanding in the Great Lakes at a rate of 20 percent yearly starting around 1820. Signs of decline became evident as early as the 1890s after the fishery reached 147 million pounds in 1889. Within the next 60 years, despite increasingly efficient fishing methods, the catch dropped off, with annual catches since 1950 averaging around 110 million pounds.

The more valuable species, such as lake trout, have collapsed from overfishing, pollution, habitat destruction and competition with invasive species such as the sea lamprey. Lake trout now survive at levels capable of sustaining commercial fishing only in Lake Superior, and even there they are supplemented with hatchery fish. The blue pike, once the top predator in the open waters of Lake Erie, and the Atlantic salmon of Lake Ontario, were major components of the early fishing industry but are now extinct. Native species have been replaced with introduced fish such as smelt, alewife and Pacific salmon. Chemical contamination compounded the damage of overfishing as health concerns limited the amount of fish that could be sold for human consumption. In 2002, every state in the Great Lakes issued fish advisories.

Another problem that has beset the lakes since the French started planting forts on lakeshores is land development, more recently in the form of summer homes, marinas and residential housing. These and other projects cause shoreline erosion that damages offshore lake habitat and related wetlands.

Urban development has been particularly damaging to the lakes. Located on major waterways, cities became centers of industrial development. Today, the region produces 60 percent of North America’s steel and 60 percent of its cars. Industry also produced vast quantities of waste that, beginning in the 19th century, were dumped directly into the lakes or into tributary rivers and streams. Raw sewage has threatened human health around the Great Lakes since the early days of urban development. For example, in 1854, a cholera epidemic hit Chicago, killing 5 percent of the city’s residents.

The dangers of industrial pollution were recognized only in recent decades when studies revealed the threats posed by PCBs, mercury and other chemicals. Many of these pollutants have settled into lake sediments, where they pose little biological risk. However, in areas frequently dredged to keep shipping channels open, the contaminants are constantly being stirred up and restored to circulation in the biological system. Cooperative management agreements among the eight states that border the lakes and with Canada are helping to cleanup the lakes, with improvements in some areas since 1970. Although measures taken under these agreements are helping to reduce pollution, the Great Lakes still require careful monitoring to preserve their greatness. Ongoing studies may turn up as yet unrecognized problems.

A Ray of Hope for the Great Lakes 
Some 300 toxic chemicals occur in the Great Lakes, including lead, cyanide, arsenic, carcinogenic PCBs and dioxins and pesticides such as DDT and mirex. The steel industry dumped so much asbestos into Lake Superior, the most pristine of the five lakes, that the floor of Superior’s entire western arm is buried under the carcinogenic substance.

Lake Erie has suffered more damage than the others from urban development. Relatively shallow at an average depth of 60 feet and lined with nutrient-rich soils, Lake Erie is perfect for death by nutrient overload. Agricultural runoff, detergents in city wastewater and the dumping of virtually raw sewage into the lake for decades by Detroit, Michigan, and Buffalo, New York, pumped the lake full of nutrients and toxic chemicals, stimulating the growth of algae and other plants that die and rob water of oxygen as they rot. The Detroit River alone carried 20 million pounds of nutrients like phosphate and poisons such as phenols and ammonia into the lake every day during the first half of the 20th century. By the 1950s, Lake Erie was clearly sick. One 2,600-square-mile portion was found to have no dissolved oxygen in its bottom waters. By the 1960s, lake shores were heaped with detergent suds, rotting algae and dead fish. In 1969, the Cuyahoga River, a Lake Erie tributary that runs through Cleveland, Ohio, was so full of toxic chemicals that it burst into flames.

An outraged citizenry brought change to Lake Erie by helping to push through legislation designed to clean up U.S. waters, most notably the Clean Water Act of 1972, which set guidelines for water cleanliness and provided federal aid for wastewater treatment. In the same year, Canada enacted its Water Act, setting standards for the amount of phosphates permitted in sewage effluents. The United States and Canada also signed the International Great Lakes Water Quality Agreement that year, promising to control phosphate flow into the lakes.

Positive changes came shortly. By the mid-1970s, fish had returned to the Detroit River and the amount of phosphate reaching Lake Erie was halved. As algal growth abated, the lake changed color from green to blue. The Cuyahoga River was no longer a fire hazard.

Lake Erie remains a symbol for what can be done when government, industry and citizens are committed to cleaning up polluted waters. Lake Erie is a promising model for other lakes. Phosphorus levels have been held to proscribed limits in Superior, Huron and Michigan since the early 1990s, and even in Erie are near the limits. Nevertheless, challenging contaminants continue to plague the Great Lakes.

Who’s in Charge of the Great Lakes? 
Among the many organizations working in the Great Lakes region, the following are key:

Council of Great Lakes Governors: The council is a nonpartisan body composed of the governors of the eight Great Lakes states—Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin. These governors first joined forces in 1983 to tackle the severe environmental and economic challenges facing the Great Lakes basin. In recent years, the Canadian premiers of Ontario and Quebec have joined the council in promoting the economy of the Great Lakes region.
International Joint Commission: The 1909 Boundary Waters Treaty established this six-member commission to help the U.S. and Canadian governments find solutions to Great Lakes problems. Three members are appointed by the president of the United States, with Senate approval, and three by the governor in council of Canada, with the advice of the prime minister. Rather than representing the views of their respective governments, the commissioners seek impartially to resolve disputes. The commission has set up more that 20 boards, made up of experts from the United States and Canada, to help it carry out its responsibilities.
U.S. Environmental Protection Agency: EPA includes a special Great Lakes National Program Office headquartered in Chicago that works to clean up Great Lakes problems with pollution and to protect the lakes from further contamination. For details, go to
State Agencies: Each of the eight states, as well as the two Canadian provinces, surrounding the Great Lakes work directly on lake issues through various agencies, such as state departments of natural resources. These agencies monitor local waters and take the lead on issuing warnings about eating contaminated fish from polluted waters.
U.S. Army Corps of Engineers: The Corps, composed of some 34,600 civilian and 650 military staff, includes on its national agenda various work projects in the Great Lakes basin. The Corps plans, designs, builds and operates water resources and other civil works projects, such as the dredging of shipping channels leading into Great Lakes ports. The Corps’ role can be controversial, as when dredging stirs up pollutants that have settled into bottom silt.
Great Lakes Commission: The commission is a binational agency that promotes development, use and conservation within the Great Lakes basin and St. Lawrence River. Members include the eight Great Lakes states, with associate members from the Canadian provinces of Ontario and Québec. Each jurisdiction appoints a delegation of three to five members comprised of senior agency officials, legislators and/or appointees of the governor or premier. Established by joint legislative action of the Great Lakes states in 1955, the commission emphasizes sustainable development when addressing lake problems and issues. The group’s activities are directed at ensuring a strong and growing economy, a goal that may sometimes conflict with its goals for creating a healthy environment and a high quality of life for all citizens.
How Are the Managers Doing?
Fifty-one state and 148 federal programs fund restoration in the Great Lakes basin, according to a federal Government Accounting Office (GAO) report released last year. Of these, 17 state and 33 federal programs are specifically targeted to the Great Lakes. The federal government spent $387 million on these restoration programs from 1992 to 2001 as well as $358 million on U.S. Army Corps of Engineers Great Lakes projects, many of which were not designed for restoration. During the same period, the states spent $956 million on specific Great Lakes cleanup and restoration programs and projects.

Lack of coordination among these various programs hinders progress in Great Lakes protection, however. The GAO declared that "an overarching strategy and a comprehensive plan are needed that clearly articulate goals, objectives, and criteria for measuring success and that establish a decision-making body to weigh the merits of, and prioritize funding for, proposed cleanup and restoration efforts." The agency also identified a lack of comprehensive, quantitative monitoring as a significant barrier to setting restoration priorities and measuring restoration progress. The GAO concluded, "The Great Lakes region cannot hope to successfully receive support as a national priority without a comprehensive plan for restoring the Great Lakes."

The report faulted the EPA’s Great Lakes guidance document, Great Lakes Strategy, 2002, as "largely a description of existing program activity relating to basin restoration" and not a strategic plan that sets priorities, establishes criteria for evaluating success and outlines funding needs and mechanisms.

"The Great Lakes need a strategic plan, strategic priorities and significantly more congressional funding to recover from decades of dredging, filling and pollution," says Andy Buchsbaum, director of NWF’s Great Lakes office. "A restoration project on the scale needed to save the Great Lakes demands comprehensive and coordinated federal action. Congress has provided much-needed funding to restore and protect some of the country’s greatest wildlife sanctuaries, including the Chesapeake Bay, Everglades and San Francisco Bay. Restoring the Great Lakes will require a similar commitment. It’s time for Congress and the administration to take strong action to restore, protect and maintain the Great Lakes now and for generations to come."

For more on the Great Lakes, read Roger Di Silvestro's article "Greatest Lakes in the World."

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