The Great Black Swamp: Toxic Algae, Toxic Relationships, and the Most Interesting Place Nobody's Ever Heard Of

November 11, 2025

In the summer of 2014, a strange thing happened to one of the largest freshwater bodies on the planet: Lake Erie’s western shore turned bright green with toxic algae that could have killed 400,000 Ohioans. Stranger still, it was kind of Patrick Wensink’s fault. Okay, partially his fault, but also to blame was industrial corn farming, greenhouse gasses, The Worst Road In America, his attraction to toxic relationships, Richard Nixon, Charles Dickens, cyanobacteria,  high school bullies, and, most importantly, the untold history of The Great Black Swamp: a large swatch of what is now Ohio and Indiana that was once a dangerous, malaria-ridden wetland.

Toxic green algae has become a global problem. While the scientific community scrambles to find a solution, Wensink discovers that the answer might be hiding in his former home, a million acres of table-flat farmland so desolate that even other Ohioans look down upon it.

Great Black Swamp: Toxic Algae, Toxic Relationships, and the Most Interesting Place Nobody’s Ever Heard Of mixes ecological reporting, Midwestern history, and memoir. As Wensink travels through Northwest Ohio, he tells us about his childhood there, his failing marriage, American history, Lake Erie, and the hopeful ecological interventions scientists are performing in the former Great Black Swamp. 

Patrick Wensink  is the author of the bestseller Broken Piano for President, Fake Fruit Factory, and several other novels and books for children. He teaches at a university in Tennessee and directs the Mountain Heritage Literary Festival.

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Advance praise for The Great Black Swamp: 

"Pull on your waders and let Patrick Wensink guide you through this surprisingly raucous history of the mysterious wetlands and modest farms of his native Northeast Ohio on his quest to understand the roles they played in shaping two catastrophes—Lake Erie’s deadly, toxic algae bloom and the end of his marriage. Insightful, vulnerable, and deadpan hilarious, The Great Black Swamp will have you believing in the power and necessity of rewilding—land, water, and self. —Erin Keane, Salon.com chief content officer and author of Runaway: Notes on the Myths That Made Me

5x7 | 240 pages | ISBN: 9781540270108