You've seen them everywhere: little accordion-folded wallet cards designed to help seafood lovers select the most sustainable fish when at the market or out at a restaurant. The simple three-color schemes -- green (good!), yellow (okay...maybe!) and red (really bad!) -- used by several different seafood consumer guides have certainly helped to raise public awareness of dwindling fish species. But a wallet card could never convey the details of why a particular fishery is more "sustainable" than another; modern fisheries are simply too complex and undergoing too many rapid changes.
For those who want to move beyond a simple three-color guide, Paul Greenberg's excellent new book, Four Fish: The Future of the Last Wild Food, chronicles the boom-and-bust cycles of four fish that "dominate the modern seafood market": salmon, sea bass, cod and tuna. But where Mark Kurlansky's genre-defining fish treatise Cod left off at the "bust" of commercial fisheries, Greenberg ventures into the little-known world of iconoclast fish breeders, genetic tinkerers and artisanal fishermen.
"Cod Plus Three," this is not.
As the title makes clear, fish is the last truly wild food that humans eat with any regularity. Yet for wild ocean fish to survive into the future we need to rethink more than just the size of our catch, but how to ease the growing pressure on wild stocks altogether using wisely-planned aquaculture.
"Fish farming" likely conjures "salmon" in most minds; as one salmon farmer told Greenberg, "Most supermarkets wouldn't even have a seafood section if it wasn't for salmon." But farmed salmon has also earned the ire of both environmentalists and fishermen due to pollution and the ability of farmed salmon to spread disease to wild populations. The core problem with farmed salmon, and, as Four Fish describes, farmed sea bass, cod and tuna, is that they were selected for domestication because they were already part of our diet, and therefore easy to market. Little to no thought was given to how they would respond to attempts at creating new domesticus subspecies.
For an alternative strategy, Greenberg suggests looking to Josh Goldman, a fish farmer based in western Massachusetts who has created the biggest re-circulating aquaculture system in the world growing Asian barramundi. Barramundi are ideal for farming -- docile, fertile, disease-resistant, and can live primarily on vegetarian feed. Or consider freshwater "tra" and tilapia, both of which grow quickly, have no interaction with wild ocean fish, and eat primarily vegetarian food. The last point is particularly important because all four farmed versions of the fish at the center of Greenberg's book are fed fishmeal -- ground up forage fish -- to provide the oils and fats required for those species to grow. (In fact, 30 percent of world's fish catch goes to make fish meal for farm animals.) In the case of Atlantic bluefin tuna, it takes an absurd 20 pounds of fishmeal to produce a single pound of tuna. That simply shifts the growing pressure on the world's fisheries much lower down the food chain, imperiling entire ecosystems, not just top predators like the bluefin.
Of course, that vegetarian feed most likely means soy, the expanded production of which has been the cause of rainforest destruction in the Amazon. However, Greenberg states that farmed fish species like barramundi, tra and tilapia are more efficient than any other form of animal protein, including chickens or pigs. Perhaps a shift away from terrestrial factory farms towards large-scale, efficient re-circulating aquaculture systems wouldn't be such a bad thing?
Even if or when the world is convinced by the irrefutable logic of switching to low-impact, highly-efficient farmed fish versus domesticated salmon, sea bass, cod or tuna, the issue remains that numerous species of wild fish are on the brink of extinction. Among several of Greenberg's suggestions is to replicate the shift that humankind made with terrestrial food production 2,000 years ago: from hunter-gatherers to herders. For example, former Maine fisherman Ted Ames proposes that we switch from large-scale commercial fishing operations to local "artisanal" fisheries. Ames documented through interviews with old-timer fishermen that there were long-forgotten nearshore populations of cod, in addition to the well-known collapsed offshore New England stocks.
To both combat the loss of such ancestral knowledge and encourage stewardship of shared resources, Ames thinks local fishermen should be responsible for specific tracts of ocean that they know best, similar to how Maine now manages its booming lobster industry. There would be little incentive for fishermen to overexploit the resources in their "plot" if they didn't have a competitor waiting to pounce on whatever is left uncaught.
This plan doesn't work for all fish, unfortunately. Atlantic bluefin tuna, which migrate from their spawning grounds in the Gulf of Mexico across the Atlantic and to the Mediterranean - at speeds of up to 40 miles per hour, no less - are caught in a no-man's land of impossible-to-enforce international treaties. Greenberg argues that the only effective way to protect the species from going extinct is an outright worldwide ban and a shift in public perception of the fish from simply "food" to "wildlife." Such shifts have precedent, as in the case of whales, and numerous nonprofit and scientific organizations are now making a similar case for the bluefin.
Greenberg gets a little cranky when he recalls the one question he can never avoid when mentioning his "damn fish book": "What fish should I eat?" Just as those wallet-sized fish guides can't comprehensively answer the question, neither can Greenberg. While being cognizant of the choices that face us as fish consumers is valuable, the far more important question is whether we choose to continue to see wild fish simply as food, or if we can make the transition, as we have with so many other species, and also see them as wildlife deserving of protection.