Lake Michigan, endlessly large, deep, and beautiful, must have seemed like it would always be there to serve humanity, no matter what we did to it. So we used it as a general purpose garbage dump until the lake’s condition got too bad to ignore. Subsequent pollution prevention efforts have helped the lake recover, so now we can relax because everything’s fine. Right?
Wrong. Lake Michigan has only one outlet, through the Straights of Mackinaw into Lake Huron, and a single drop of water takes about 99 years to leave the lake. Many of the chemicals that have contaminated it are still there, even though they are no longer being added to the water, because they are "persistent," or nonperishable. Additional pollutants still enter the lake via the atmosphere and in other ways.
The quality of the water has improved since the 1970S. Due largely to legislative efforts, levels of phosphorus and other toxins are down, and many species of fish are slowly throwing off the chemicals they have accumulated. Some of the most important pieces of legislation have been the bi-national agreements from the International Joint Commission of the United States and Canada (IJC). The IJC, composed of three members from each of the two countries, has many responsibilities, including researching problems related to the Great Lakes and making recommendations to both governments, although these recommendations are not binding.
The IJC was created as part of the Boundary Waters Treaty of 1909. At that time, the IJC conducted a study of Great Lakes pollutants, including phosphorus, which it found to be a cause of eutrophication — oxygen depletion caused by the decomposition of excess algae, the overgrowth of which was stimulated by excess nutrients, especially phosphorus. This study and its recommendations inspired not only some highly successful controls on phosphorus but the Great Lakes Water Quality Agreements.
The first of the agreements, in 1972, called for further research, monitoring, and general pollution control. The second, in 1978, built upon the first, limited loading of some contaminants and called for elimination of others. The third, in 1987, widened its breadth and emphasized the health of ecosystems in the Great Lakes Basin.
The EPA, in its Lake Michigan Lakewide Management Plan Fact Sheet of October, 1993, identifies a number of pollutants, and divides them into three categories: critical, pollutants of concern, and emerging. Critical pollutants are PCBs, mercury, DDT, dioxin, chlordane, furan, and dieldrin. They are persistent and/or bioaccumulative and cause lakewide problems. Pollutants of concern are those that cause local problems or whose lake levels are increasing: toxaphene, chromium, hexachlorobenzene, copper, PAHs, arsenic, lead, zinc, cadmium, and cyanide. Emerging pollutants are those with the potential to do serious harm: atrazine, selenium, and PCB substitutes.
Enforcement of clean water regulations (including bans on DDT and restrictions on PCBs and other chemicals) has improved the waters of Lake Michigan and the other Great Lakes. Legislation such as the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, and its amendment; the Superfund Amendments and Reauthorization Act; the Clean Water Act; the Toxic Substances Control Act; the National Environmental Policy Act; and many others, also have helped get the waters cleaner.
Private industry is polluting less, voluntarily and because of regulations, including those requiring certain industrial facilities to publish Toxic Release Inventories that detail how much of certain toxins they generate and what they do with it. Not all facilities or all chemicals are covered by these inventories, but the available data show that releases of toxic chemicals are down, according to the EPA.
That, in itself, is good news — but perhaps not good enough. The Great Lakes: An Environmental Atlas and Resource Book explains that even though water concentrations of particular chemicals may be so low as to be undetectable, those chemicals can still accumulate to substantial levels.
Additional pollutants — up to 90 percent of some pollutants — also enter the lake through the air. Airborne pollutants include lead, largely from vehicle emissions; PCBs; mercury; atrazine, a non-bioaccumulative and possibly carcinogenic pesticide; dioxin; acid rain; and others. The Chicago-Gary area is one of the biggest perpetrators, though pollutants also are carried in on currents from far away.
On the bright side, the Lake Michigan Federation notes that chemicals can also leave the lake through the air, through a process called "volatilization," the evaporation of gasses through water. Pollutants may cycle back and forth this way; PCBs will evaporate from the lake in winter and settle back in summer. Encouraging is that, in 1997, the United States and Canada have signed the Great Lakes Binational Toxic Strategy, aspects of which focus on air pollution. Parts of it are already being implemented.
Fish Food?
How does Lake Michigan’s water quality affect the fish? Pretty much as you would guess. Chemicals such as DDT, PCBs, dieldrin, and chlordane have bioaccumulated in Lake Michigan fish, especially in the larger predators such as coho salmon and trout, and the National Wildlife Federation reported in 1989 that eating eight meals per lifetime of lake trout increases a person’s risk of cancer. DDT is still present in fish despite its having been banned, and so are PCBs, though levels are down from those in the mid‘70s. These toxins are still entering the food supply.
Zebra mussels are among the accidentally offending (and offended) organisms; they and other bottom feeders eat the toxins that settle at the bottom of the lake. Zebra mussels absorb more toxins than average seafood because they are fattier, and many of the chemicals in the sediment are stored in fat. But all bottom feeders take in pollutants such as PCBs and mercury, which bioaccumulate. So when other fish animals eat the bottom-feeders, the pollutants they’ve accumulated get passed along. The top predators, including humans who eat lake fish, get the biggest doses.
The EPA reports that most human exposure to lake pollutants comes from eating the fish. As recently as September 12, 1996, an article in the New England Journal of Medicine warned that children whose mothers ate lake fish while pregnant had poorer memories, lower IQs, and attention problems. According to The Great Lakes: An Environmental Atlas and Resource Book, "a person who eats one meal of lake trout from Lake Michigan will be exposed to more PCBs in one meal than in a lifetime of drinking water from the lake."
Airborne and land-based wildlife continue to suffer, as well. Because of toxic contamination, fish-eating birds are born with crossed bills, causing them to starve to death eventually. Thinning egg shells cause nesting failures. Cancer; population declines; reproductive, birth, immune, metabolic, anatomical, and behavioral defects plague animals throughout the Great Lakes Basin.
Oddly enough, the clarity of Lake Michigan’s water is improving, due to the very zebra mussels who are part of the mess at the bottom. Lining rocks, boats, pipes, piers, snails, and each other, they filter foodstuffs out of about a quart of water per day. Ironically, increased clarity is allowing more sunlight into the historically dark lake, encouraging plant and animal life to grow where it never did before.
Still, what grows may not be the old favorites fishing enthusiasts like to see, and proposed solutions on that score can be almost amusingly wrongheaded. An article in the Chicago Sun-Times, May 10, 1999, reported that sport fishers want phosphorus added to Great Lakes water to increase algae growth to provide more food for the fish they like to catch. Numbers of those fish are declining, they say. According to the Sun-Times, officials have neither embraced nor rejected this idea. Thankfully, Cameron Davis, Executive Director of the Lake Michigan Federation, was on hand to call this proposal "ill-informed," noting that Lake Michigan’s ecosystems are very delicate, and that any changes could have an "unimaginable cascading effect. "
Areas of Concern
In an effort to further the health of the lake, the IJC has established a list of ten Areas of Concern (AOCs), defined as geographical areas too polluted to support human uses. One close to home is the Grand Calumet River/lndiana Harbor Ship Canal. It is a mess. Home of seven Superfund sites and hundreds more hazardous waste sites, it dumps contaminated sediment, and water filled with storm and sewer overflows and industrial waste into the Lake. Another is the nearby Waukegan Harbor, the surrounding area of which is home to three Superfund sites because of contaminated soils and sediments.
The Kalamazoo River AOC, which drains PCBs into Lake Michigan, is a Superfund site because of PCB contamination working its way up the food web, possibly causing nesting failure of bald eagles in the area. The Great Lakes Water Quality Agreement of 1987 calls for Remedial Action Plans (RAPs) for these AOCs and the 33 others surrounding all of the Great Lakes, and plans to clean them up are under way, but much more needs to be done, write IJC staffers.
Other dangers to Lake Michigan’s water quality include contaminated soils; groundwater seeps through them into the lake, picking up both toxins from industry and pesticides from agriculture. Chemicals from agricultural runoff add pesticides and substances that cause eutrophication to the lake, and urban runoff adds road salt, lead, asbestos, and other pollutants from cars and industry. Another potential danger, notes the Lake Michigan Federation (LMF), is directional oil drilling, meaning, in this case, drilling from land for oil under Lake Michigan. The LMF fears that fires or explosions of the wells could send gas and oil into all surrounding water.
Efforts to improve water quality continue, mostly in the form of research and prevention of additional polluting. One project, the EPA Great Lakes National Program Office (GLNPO) Lake Michigan Mass Balance Study, analyzes the balance between chemicals entering and leaving the lake, and how those chemicals behave in ecosystems. Another GLNPO project, the Lake Michigan Lakewide Management Plan (LaMP), is designed to restore the lake to ecological health and usefulness to people by, basically, reducing some pollutants to acceptable levels and virtually eliminating the persistent, bioaccumulative ones too dangerous to tolerate. Actions being taken under this plan include monitoring pollution from tributaries and from the atmosphere, and various cleanup efforts involving Indiana, Wisconsin, Milwaukee, Chicago, the Manistee Lake (MI) AOC, and the Lincoln Park Gun Club. Future plans under the LaMP include further cleanup of sediment, coordination of control efforts, codifying air quality regulations, and, of course, more research and monitoring so that the Great Lakes can be managed properly.
The GLNPO also is working with the government of Canada on a "Virtual Elimination Project" to combat the release of persistent pollutants, and various government agencies are taking a partnership approach with private industry to encourage them to voluntarily control their toxic releases. Offering "market-based" incentives in the form of financial rewards or regulatory relief in exchange for pollution control has been very helpful, according to the IJC.
Legislation and regulation have been effective, concludes the IJC, but the agency fears that governmental support and funding for the environment is fading and that the current desire to shrink government and its influences may weaken the programs that have helped the Great Lakes begin to recover. In following federal policy of shedding responsibility for pollution control programs to state and local authorities, they note, goals of those programs may get watered down by the states. Already, their web site notes, AOCs aren’t getting the attention they deserve. Also, they raise questions about whether measures currently in use, relying on inefficient government bodies and voluntary cooperation, are good enough. Can Lake Michigan wait while we find out?
Resources
Aquaticus, Journal of the Shedd Aquarium
The Great Lakes: An Environmental Atlas and Resource Book, jointly published by the EPA Great Lakes National Program Office and the Government of Canada in 1995
Lake Michigan Federation