This is a rollicking, eye-popping, scary, sad tour of one of the world’s watery wonders, the Great Lakes. Readers will appreciate the vivid history and sober analysis it offers of the serious threats the lakes face today. From invasive species to water diversion to changing water levels, the author explores each issue in colorful and absorbing detail.
Dan Egan is a reporter for the Milwaukee Journal Sentinel, and has been covering the Great Lakes for years. His anger at failing policies and government inaction is evident in every chapter.
His main target is the St. Lawrence Seaway, an engineering marvel when it was opened in 1959 with great fanfare by President Eisenhower and Queen Elizabeth. (I can remember this, because my great aunt, who lived in Cleveland, gave me a commemorative stamp issued for the occasion.)
But Egan says the Seaway “never lived up to the hype,” and instead produced a cascade of environmental disasters that have brought the Great Lakes to the brink of the death his title refers to. Ships sailing 2300 miles from the Atlantic Ocean through the system of locks and canals, rivers and lakes to the heart of the continent have carried a biological time bomb. They have deposited the majority of 180-plus non-native species now living in the lakes, and unraveled ten-thousand-year-old ecological webs. The problem is the ballast water used to stabilize the ships: “a system custom-made to deliver invasives,” as Egan puts it. Discharges of ballast water brought from the other side of the world inevitably allowed foreign critters to colonize Great Lakes waters.
Dan Egan (c) Mike De Sisti
Egan wants to close the Seaway to ocean-going ships. I live in Duluth, and I love seeing ships sailing in with huge Danish-built wind generators lashed to their decks, or waiting just outside the port to load up with grain destined for Africa. But Egan points out that 95-percent of the Seaway system’s cargoes—iron ore, coal, cement, salt—are carried on “lakers.” He says “salties,” as the ocean-going ships are called, should be required to unload their cargoes onto trains for the journey from the ocean to the heartland. He suggests the federal government could pay for the added expense, and it would cost less than we currently pay to deal with damaged infrastructure and ecosystems caused by the invaders. Closing the door to future invasions, he suggests, would allow us to concentrate scarce resources on other serious problems such as pollution from fertilizer, unstable water levels, and threats of water diversion.
Ballast water exchange
In the mid-to-late 1990s, the government began requiring ships to exchange ballast water in mid-ocean, filling their tanks with salty water which is thought to kill most freshwater organisms. In 2012 the Coast Guard, followed by the Environmental Protection Agency, set rules for ballast water treatment, including filtration and disinfection. In 2015 an appeals court ruled those standards are not strict enough to protect U.S. waters, but they remain in place while legal battles continue. These requirements have no doubt contributed to the fact that no new aquatic nuisance species have been discovered in the Great Lakes since 2006. [Correction: Thermocyclops crassus was found in the western basin of Lake Erie in samples collected from 2014 through 2016, after appearing in Lake Champlain in 1991.] Egan argues it’s only a matter of time before we find the next one, and it could be even more damaging than zebra and quagga mussels, which clog water intake pipes and other infrastructure, costing cities and industries millions annually.
Egan’s engrossing description of the arrival and impacts of the most destructive of these invaders provides a persuasive reminder that everything in nature is interconnected. When early European explorers (we might call them the first invaders) beheld the Great Lakes, the shining waters were teeming with fish. As late as the 1940s, the inland seas yielded 100 million pounds of fish to commercial harvesters each year.
Sea lamprey
The first major disruptor made its presence felt in the mid-1930s. The blood-sucking sea lamprey had swum into the Great Lakes through shipping canals built in the 19th century and preyed on trout, whitefish, herring, and other native fish. The annual commercial trout harvest on Lake Michigan plummeted from nearly 6.5 million pounds to zero by 1954.
Sea lamprey. Photo courtesy T. Lawrence, Great Lakes Fishery Commission.
Egan tells a dramatic story of the discovery of a poison specifically targeted at sea lampreys. A singularly dedicated World War II veteran named Vernon Applegate spent his years as a graduate student at the University of Michigan living alongside lamprey-infested rivers to study their life cycle. He learned that they spend five years as tiny worms buried in the mud, then suddenly emerge and swim in hordes downstream to the lakes. That time they spend in rivers makes them vulnerable to death by poisoning. At a remote lab in a converted Coast Guard station on the tip of Michigan’s lower peninsula, Applegate and his crew methodically tested industrial chemicals—as many as 50 a day—to find a compound that would kill lamprey but not other fish. They found a chemical that worked, and fisheries managers quickly brought the invader under control. But the native lake trout population had crashed, and fisheries managers weren’t sure it could be revived.
Alewife explosion
The next arrival to disrupt the ecosystem was the alewife. Incredibly productive, alewives exploded in population just as trout and other big fish were declining due to overharvest and lamprey predation. In three years (1962-65) alewives went from 17 percent of the fish population in Lake Michigan to 90 percent. Then in 1967 millions upon millions of these small fish washed up dead on Chicago beaches, smothering 30 miles of shoreline in “rotting fish goo.” They weren’t dying from a poison, or toxic bacteria; as a salt water species trying to live in fresh water, the alewives were under constant physical stress, with kidney and thyroid problems. The final blow came from sudden swings in water temperature unlike any in the ocean. Their bodies just couldn’t handle the multiple challenges.
Salmon for sport
Meanwhile, the deliberate introduction of another species set the stage for further disruption. In the mid-1960s, Michigan’s Department of Conservation (now DNR) decided to give up on the native lake trout and introduce a new predator fish that would be more fun for anglers to catch. Howard Tanner was brought in from Colorado to make it happen. In the West, Tanner had seen conservation departments stock rivers in artificial pools created by dams, “essentially, a blank canvas for a biologist to construct an ecosystem from scratch,” explains Egan. And Tanner got used to planting fish. When he returned to Michigan, he saw the big alewife population as ideal food for Pacific salmon, and he saw the Great Lakes as a place to promote recreation rather than as a source of fish protein for the human population. He got some eggs from a hatchery in Oregon, raised them to finger size, and then planted them into the Platte River near Traverse City. The experiment was wildly successful, quickly generating a powerful sport fishing industry, with charter fishing operations, boat builders, and entire lakeside communities cashing in. It was all in direct contradiction to federal policy at the time, which was to rebuild the populations of trout and other native species.
Wildlife managers stocked salmon for thirty years, and the species was also great at reproducing naturally. But the system proved unsustainable. By the early 2000s, invasive zebra and quagga mussels arrived on the scene, gobbling up the plankton that formerly fed the alewives, whose decline hit the salmon hard, and the pyramid collapsed.
Egan tells equally intriguing stories about the exotic mussels and other more recent invasive introductions, such as the round goby, first found in the Great Lakes in 1990. He also has chapters about Asian carp, the spread of pests from the Great Lakes to lakes in the western U.S., what toxic algae can do to city water supplies, the threat of water diversion, and the impacts of climate change.
One odd sign of hope is an almost unbelievable development, the evolution of a new food web. Native fish are starting to eat the invaders. Native whitefish once depended on bottom-dwelling shrimp-like organisms, which vanished with the arrival of zebra and quagga mussels. Now fishermen are catching whitefish with invasive mussels and round gobies in their stomachs. The whitefish seem to be changing their diet to include this novel food. Perhaps the Great Lakes are more resilient than history would suggest, but Egan argues it’s up to us to give them a chance.
The book offers a wealth of well-researched information presented in an engrossing narrative of history, science, and enough politics to suggest how improbable it is that Egan’s proposal to close the lakes to ocean-going ships will ever happen.
