Eighty percent of seafood consumed in the United States is now imported from all over the globe. The crab in “Maryland” crab cakes may come from Indonesia, “Cajun” shrimp from Thailand, “Caribbean” mahi-mahi from Ecuador. Almost half the seafood consumed globally is now from fish farms, or aquaculture, including all or most of the supply of such U.S. consumer favorites as shrimp, salmon, tilapia, and catfish. Acknowledging that the vast majority of our meat and poultry now come from farms, many experts ask, why should fish be any diffrent? In Swimming in Circles, Paul Molyneaux explores this very question.

As a native of working-class eastern Maine, Molyneaux paints a personal portrait of aquaculture, starting with his truck-driving job. Leaving the Maine-Canada border at midnight, Molyneaux rushes an overweight truckload of farmed salmon over icy roads to Logan International Airport in Boston at eighty miles per hour. Receiving only $120 for fourteen hours of driving, he does not have enough funds to bribe the airport stevedore, and unloads the truck himself. Like others in eastern Maine in the late ’80s, Molyneaux expected the local aquaculture industry to grow. It did at first, but its growth ultimately was curtailed by salmon disease, controversy over environmental impacts, and low-cost farmed-salmon imports from Chile and elsewhere.

Molyneax goes on to detail the explosive growth of shrimp farms along the Pacific coast of Mexico. Following a law allowing privatization, many members of Mexican ejidos, or fishing collectives, sell their coastal land for the development of shrimp farms. But the shrimp gold rush proves ephemeral for many. The spread of virulent shrimp diseases closes farms, and coastal residents are left to seek jobs picking chilies, or in maquiladoras along the U.S.-Mexico border. The parallels between Maine and Mexico are inescapable. And yet Molyneaux describes a well-intentioned United Nations fisheries officer who pursues shrimp-farm development as a means to spur income growth in poor countries. One aquaculture “techno-optimist” even invokes Manifest Destiny as a reason for expanding fish farms in ocean waters.

Molyneaux also chronicles his brief career in Maine’s final “virgin” fishery, sea urchins. He makes a reasonable living catching urchins from a small hand-rowed dory. But other fishermen invest in bigger boats and bigger engines, which require a concomitantly bigger catch to pay for their equipment. When political pressure from fishermen stops the government from placing adequate limits on the urchin catch, the fishery spirals downward in less than a decade. Wild fisheries around the world have experienced the same cycle of decline; fishermen invest in technology that allows them to catch more fish, leading to overexploitation.

Given this troubling background, readers cannot help but ask themselves about the future of fisheries in a global economy. Some organizations, such as Environmental Defense (where I work), are pursuing a range of strategies to change the economic rules of the game. For example, allocating to fishermen a fixed percentage of the total allowable annual catch set by fishery regulators provides them with an incentive to conserve. Such “catch share” programs were recently made possible in U.S. waters by fisheries legislation passed by Congress in December 2006. Similarly, working with corporate seafood purchasers to establish policies that favor seafood farmed using environmentally preferable methods creates an economic incentive for better aquacultural practices. Although such initiatives are not discussed in Molyneaux’s book, they have resulted in a smattering of shrimp farms operated in a relatively environmentally responsible manner.

It is no surprise that Swimming in Circles is ultimately about current economic systems and globalization. What do these forces portend for the future health of the oceans and for the future livelihoods of coastal people who are too often dispossessed? Molyneaux asks a number of provocative and sometimes disturbing questions, many of them applicable to a wide range of human endeavors besides seafood production. But it is his vignettes, from Maine, Mexico, and elsewhere, that ultimately make this book a rewarding read.