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Dan Egan is a reporter for the Milwaukee Journal-Sentinel, acclaimed for his coverage of the Great Lakes. He is the Brico Fund Senior Water Policy Fellow in Great Lakes Journalism at the University of Wisconsin-Milwaukee School of Freshwater Sciences, and a two-time Pulitzer Prize finalist in Journalism. His most recent book, The Death and Life of The Great Lakes (2017, W. W. Norton & Company) is journalism, science writing, and environmental advocacy with vision of its own. It depicts the history of circumstances that brought the Great Lakes their largest modern day problem; the current social and scientific details of that problem; as well as advocating for directions toward fixing the problem with long-term promise.  

Beyond industrial pollutants, non-native species can upend an ecosystem in ways that are hard to predict. Lake Michigan is thought to contain 186 non-native species (p. xvi). The possibility of problems from invasive species (non-natives that are also supposed troublemakers) in our Great Lakes is in no way new. As Egan details, we have been fighting with invasive sea lamprey (to a draw with poison) since the 1950s (p. 53) and taming the alewives (with non-native salmon) since the 1960s (p. 70). But the kind of solution we enlist to fight them off (poisoning/non-native predators) is in no way general, and the latest round of invasive attacks, from quagga mussels to Asian carp, seem to put the entire ecosystem in jeopardy.

At root, the issue can be traced to the fact that humans opened up the waters of the Great Lakes to the Atlantic Ocean on the one hand – through the St. Lawrence Seaway – and the Gulf of Mexico on the other – through the Chicago River canal. The reasons for doing so were economic, but the economy has changed. The Chicago River canal – the route by which the voracious Asian carp threaten the Great Lakes – is of questionable economic import today. Meanwhile, the problems coming down the Seaway can be mitigated by pieces of legislation, removed from the initial Clean Water Act, requiring that ships coming from overseas flush their ballast water before coming down the Seaway. But in the case of the Seaway, the problems have already arrived.

The quagga mussel is the heir apparent to the zebra mussel and owns the Lake Michigan sea-floor. Like the zebra mussel, the quagga came from the Caspian Sea and was introduced to Lake Michigan via ballast water dumping. They have found themselves quite a home here, but at the expense of the food chain. Mussel shells fill some beaches along the western shore, but as Harvey Bootsma of the UW-Milwaukee School of Freshwater Sciences says, it is ‘the tip of the iceberg’ (Egan, p.129); one can nearly walk across Lake Michigan at some points on a bed of mussels. Mussels feed on plankton. Perch and smelt also feed on plankton, and are the basic food source for trout and other larger fish, not mussels. By draining the lake of this fundamental food source, the mussels are literally draining the life out of the lake year-round.

But the problems are more complex than this. The mussels are changing the chemistry of the lake, too. Egan details a case in which birds die from botulism that sprouted on the sea-floor (p. 130). It started with the water clarity produced by the mussels, leading to more sun on the sea-floor and a bloom in sun-loving plant Cladophora. These in turn died in abundance, eating up large amounts of oxygen in decay, creating anoxic conditions, and opening the door to the botulism outbreak. It is believed the mussels take in these bacteria (the botulism), and are eaten by round gobies, who become sick and easy prey for birds, which then themselves die. Since 1999, when botulism became an issue, 100,000 birds have been killed in the region.

Such problems can most easily be prevented in the future by a frustratingly simple policy – shut the doors on the invasive species. Getting out of the current perilous scenario does not appear easy. Egan details what happens when we’ve tried engineering our way out of such problems. In the 1980s, non-native salmon were introduced to moderate the alewife problem plaguing Milwaukee beaches, in what was also an economic boon for the game fishing industry. But the only thing that eats the mussels is the goby, also an invasive species from the Caspian, which resides in our waters in abundance. Salmon typically eat schooling fish, which the goby is not. Hope lies in the fact that the native whitefish, lake trout, and non-native – though already introduced – brown trout can eat the goby. But there is a question if the matter is already too far out of hand.

At an event in downtown Chicago, co-sponsored by the Alliance for the Great Lakes and the Metropolitan Planning Council, Egan was interviewed by Monica Eng of WBEZ in Chicago. At the event, Egan actually felt compelled to raise and address the question of “Why don’t we just give up?” Of course, there are people that just don’t care about environmental issues, but there is a quiet understanding that those people are either to be converted or ignored. Egan actually addressed this question and his response was noteworthy. He didn’t say that, somehow, anyhow, our Great Lakes will never die. He said, like any living thing, you know it will die, but that does not prevent you from fighting for its life. In the end entropy gets us all, but are we to be alarmed? In email correspondence, Egan downplayed any alarm bells this may have triggered. “It’s simply the next chapter that is unfolding on the lakes right now — a surge in native species that are figuring out how to make a living off gobies.” Nevertheless, it is a fair question of whether the mussel population will be tamed before it chokes our lakes.

As Egan notes in the context of fighting against the invasive species problem in general, it seems like we are simply waiting for a signature moment – like the 1969 burning of the Cuyahoga River – around which action can be galvanized. And in the meantime, the notion that environmental advocacy is a fight for life, is one which resonates. Dan Egan takes that fight seriously. He takes the fight more seriously than anyone I have met before. Not only does he want to get it right. He spends as much energy explaining to the people what is correct in terms they can understand. That is the only way to steer this ship out to sea.

Written by Casey S. Schroeder for the Milwaukee Area Science Advocates. Casey is a frequent contributor to MASA. More of his work can be found at

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