The author of The Book of Sharks, Imagining Atlantis, and Encyclopedia of the Sea turns his gaze to the tuna—one of the biggest, fastest, and most highly evolved marine animals and the source of some of the world’s most popular delicacies—now hovering on the brink of extinction. In recent years, the tuna’s place on our palates has come under scrutiny, as we grow increasingly aware of our own health and the health of our planet. Here, Ellis explains how a fish that was once able to thrive has become a commodity, in a book that shows how the natural world and the global economy converge on our plates.

The longest migrator of any fish species, an Atlantic northern bluefin can travel from New England to the Mediterranean, then turn around and swim back; in the Pacific, the northern bluefin can make a round-trip journey from California to Japan. The fish can weigh in at 1,500 pounds and, in an instant, pick up speed to fifty-five miles per hour.

But today the fish is the target of the insatiable sushi market, particularly in Japan, where an individual piece can go for seventy-five dollars. Ellis introduces us to the high-stakes world of “tuna ranches,” where large schools of half-grown tuna are caught in floating corrals and held in pens before being fattened, killed, gutted, frozen, and shipped to the Asian market. Once on the brink of bankruptcy, the world’s tuna ranches—in Australia, Spain, France, Italy, Greece, Turkey, and North Africa—have become multimillion-dollar enterprises. Experts warn that the fish are dying out and environmentalists lobby for stricter controls, while entire coastal ecosystems are under threat. The extinction of the tuna would mean not only the end of several species but dangerous consequences for the earth as a whole.

In the tradition of Mark Kurlansky’s Cod, John Cole’s Striper, John Hersey’s Blues—and of course, Ellis’s own Great White Shark—this book will forever change the way we think about fish and fishing.