The Death and Life of the Great Lakes by Dan Egan

    This history of the Great Lakes reads like a long series of ecological calamities. The book is well-written, but feels repetitive, I think, because the ecological history of the Lakes is repetitive. It is marked by a series of invasions and die-offs that have destroyed almost every native animal that lived in the lakes before European colonization. Chief among the invasive species that have changed the lakes are Alewives, a small fish, and two small shellfish: zebra and quagga mussels. The mussels have made the lakes' water clear by eating all of the plankton and algae that would otherwise live in it, starving out all other life.

    There have been two major engineering works that opened up the Great Lakes to invasive species. The "front door," is the series of canals built in the 19th and 20th centuries culminating in the St. Lawrence Seaway (opened in 1959), allowing container ships from the Atlantic to reach Great Lakes ports. The second, the "back door" is the Chicago Sanitary and Ship Canal, built in 1900 to flush sewage down the Mississippi River, as well as to open it up to transit from the Great Lakes. It reversed the flow of the Chicago River to do so. But the effect of both of these openings has been to expose the native species of the Great Lakes to a massive amount of competition, killing them. Egan's thesis is that the first and foremost of the ecological restoration projects should be to close these waterways, which he argues have little economic benefit, so that there can at least be no more damage from them as biologists work to restore habitats. Technically, there is a third: the Erie Canal; but the Erie Canal is no longer in use since it isn't big enough for modern ships, and was made obsolete by railroads and modern trucking. In fact, the St. Lawrence Seaway also doesn't get nearly as much use as expected. Since the modern shipping container was invented (right around the time the Seaway opened), ships have gotten larger. In the 1960s, container ships were already getting to be 100 feet wide (20 feet wider than the biggest locks on the Seaway, and today the largest ships are twice as wide as the Seaway's locks. Compare the Seaway with the Panama Canal: the St. Lawrence Seaway can fit ships 740 feet long and 78 feet wide while the Panama Canal can fit ships 1,215 feet long and 168 feet wide. And there are already significant numbers of container ships that cannot fit into the Panama Canal. Below is a chart of the sizes of ships that can travel through different canals/ports around the world. Beam means width.

    I think I took the opposite message of the book that the author wanted. He clearly thinks that since the St. Lawrence Seaway and the Chicago Canal don't get much traffic anymore, that they should be closed since they have a negative impact on wildlife. But from reading about how all the native life seems to be dead already, I came away thinking that we are overdue for a major expansion of the Seaway. There is still lots of internal cargo traffic in the great lakes, but overseas traffic has dropped from 23 million tons in the 1970s to 6 million tons, accounting for just 5% of Great Lakes shipping. In 2015, only 455 ships crossed the Seaway.

    I am curious what the state of the lakes is right now, since this book is a few years old and it seems like some of the ecological changes can happen fast. Egan writes that Lake Michigan is just a giant bed of exotic mussels, and its mass is seven times more quagga mussels than prey fish, which sustain the salmon and trout. And of the fish that are left, most are other invasives or exotics, or they were stocked into the lakes to be good sport for fisherman. So I am not sure if the environmentalist interest in the Great Lakes is that strong anymore in the sense of protecting nature for nature's sake. At this point, I'm very hazy on what nature is left, and the book left me with the impression that the lake should be preserved for fishermen. That sounds good to me as someone who likes to fish, but not nearly as compelling as the Everglades or the Amazon rainforest. I think I came to disagree most with the author at the end, when he discusses how the interests of environmentalists and sport fishermen diverge. Because certain policies that are good for native species are bad for other stocked fish that are more fun to catch. I feel like if there is no good solution there, then the best thing for the people of the Great Lakes would be to open them up to more traffic with stringent regulations on ballast water being expelled and replenished far away in the ocean before entering the Seaway. But I admit humility because I know so little about this.

Miscellaneous Facts:

• Waves in the Great Lakes have reached up to 25 feet tall.
• There are approximately 6,000 shipwrecks at the bottom of the Great Lakes.
• 3 percent of the water on Earth is surface freshwater, and of that, twenty percent is contained in the Great Lakes.
• One of the biggest ways that invasive species travel across water is in the ballast tanks of cargo ships.
• The last Ice Age lasted from 2 million years ago to 10,000 years ago.
• About 50 percent of the surface freshwater in the 50 states are within the boundaries of Michigan.