Plenty of Fish in the Sea—Or Not
A look at the future of our scaly friends.

Four Fish: The Future of the Last Wild Food
Paul Greenberg
Penguin Press, 284 pp.

Which is better: farmed or wild fish? Paul Greenberg’s impressive new book Four Fish: The Future of the Last Wild Food tackles the answer to this seemingly simple question. Four Fish is part personal history, part food culture, and part natural science. Think David Foster Wallace’s “Consider the Lobster” expanded into “Consider the Salmon, Bass, Cod, and Tuna,” but with fewer footnotes and less self-consciousness. Greenberg’s writing about seafood and the environment has often appeared in The New York Times. Perhaps more importantly, he is an avid fisher himself, having grown up by the water and spent many childhood hours in a fishing boat.

As the title suggests, the book is divided into four chapters containing the stories of how humans mastered the management of salmon, bass, cod, and tuna first through fishing and then farming. In investigating these four fish, Greenberg hops across continents to Alaska, Cape Cod, Israel, and Greece. The prose is vivid and arresting, which is well-suited for the majesty of the great outdoors that he writes about. One especially poignant section follows the life cycle of a salmon from larvae in the Connecticut River to smolts in Long Island Sound to adult salmon in Greenland and finally back to New England. All this to end up as “faceless orange slabs of supermarket product.” My cursory summary does not do justice to the salmon’s epic journey, with which Greenberg manages to interweave natural history and his personal history.

Ultimately, it is economics and politics, argues Greenberg, that play crucial roles in influencing which fish are domesticated. For example, research into farming the European sea bass in the 1950s was heavily funded by the Israeli government because the Israelis were concerned about “food sovereignty” and because bass, once a rare fish for special occasions, fetched a handsome price on the export market.

Those familiar with the artificial lives of farmed cows or chickens would not be shocked to learn that farmed fish live similarly unnatural ones. Instead of their natural diet of zooplankton, which is difficult to domesticate, juvenile bass are fed rotifers and artemia. Adult fish are given feed made of ground up wild fish. The most crucial step in domesticating fish is controlling their reproductive cycle, which is done by implanting a microscopic polymer-based sphere that slowly releases hormone into the fish’s bloodstream.

Greenberg has a knack for finding good stories, and the story of Yonatan Zohar, the Israeli endocrinologist who likens himself to an “ob-gyn for fish,” is one of many rich with suspense and empathy. Over decades, Zohar’s research team picked through tens of thousands of fish heads for the pituitary gland to investigate the hormonal profile of bass. After a sample of 10,000 pituitary glands came back from the laboratory as “degraded,” they spent another year harvesting another 10,000 glands, only to get the same results. A lucky realization prevented all those years of work from going to waste: the spike in the lab’s analysis was a new hormone, not a sign of degradation.

As great of a storyteller as Greenberg proves to be, the book contains real recommendations on how to fix the fishing and aquaculture industries. It is also refreshing in its lack of self-righteousness. Greenberg is sympathetic to the lives of the fishermen whose livelihoods depend on the ocean as well as the ecological realities of our actions. His sensible recommendations include reducing the fishing effort – we must think of wild fish as occasional indulgences – and to choose domesticated fish that are better for the environment. The fish we eat were originally chosen because they were popular and could turn a profit for entrepreneurs. They are not, however, environmentally sustainable when one takes into account statistics such as it takes twenty pounds of feed to produce one pound of flesh on a tuna.

In highlighting only four fish, Greenberg achieves a neat structure to his book but undermines what should an important takeaway: the ocean ecosystem is a vast web of relationships, and everything really is connected. In December 2009, Greenberg wrote an op-ed in the New York Times on the ecological consequences of the fish oil industry. Most fish oil derives from a relative to the herring called menhaden. Menhaden are filter-feeders, which means they eat algae in the water. Thus they play two important roles in the ecosystem: keeping water clean and converting their food into the prized omega-3 fatty acids that give fish oil its health benefits. Menhaden are not fit for human consumption, but they are often ground up in animal feed, and many of the fish we do eat, including bluefin tuna and striped bass, feed on menhaden in the wild too. The humble menhaden is not going to appear on any restaurant menus, but without it, neither can a premium slice of otoro. The reality is that any conservation movement needs its stars – just ask the World Wildlife Fund and the giant panda, so here the salmon, bass, cod, and tuna share top billing. While the book focuses only on four fish, unregulated aquaculture and overfishing hold consequences for the entire ocean ecosystem.

Sarah Zhang writes and works in a neuroscience lab in Cambridge, MA.