The Dirty Truth Behind America's Obsession With Shrimp

The following is an excerpt from Let Them Eat Shrimp: The Tragic Disappearance of the Rainforests of the Sea by Kennedy Warne. Copyright 2011 Kennedy Warne. Reproduced by permission of Island Press, Washington DC.

Shrimp and mangroves. Mangroves and shrimp. The two are intertwined, ecologically and economically. They are like a pair of orbiting stars, though one shines at the expense of the other. The bitter irony is that without mangroves, there would be no shrimp. Mangroves are the natural nurseries of the shrimp species that are farmed commercially, just as they are for so many other marine creatures. In the wild, shrimp begin their lives in offshore waters, where the adults spawn. Then, carried inshore by currents, and perhaps aided by their own swimming, the larvae take up residence in sheltered inshore habitats where mangroves flourish. There, living and feeding in the shelter of the tangled limbs of the mangrove forest, they grow and molt until they are ready to migrate back out to sea.

Technology has short-circuited this ecological connection. Industrial shrimp hatcheries have taken the place of mangrove nurseries. From the viewpoint of commercial shrimp farming, mangroves are superfluous. And that is exactly what they have become on the ground. In most developing countries, it is not possible to visit mangroves without seeing the hobnailed bootprint of a rapacious industry. How did aquaculture come to be such a destructive force, and shrimp the mangroves' nemesis?

Let's go back to the origins of the industry. The oldest known guide to aquaculture was written in 475 BC and consists of advice from a Chinese administrator named Fan-Li to the ruler of a neighboring kingdom on how to get rich by culturing carp. The document contains information about pond size, stocking rates, nutrition, and predator control. (To ward off fish-stealing birds, writes Fan-Li, turtles should be deployed as "heavenly guards.") Follow his instructions, Fan-Li tells the king, and by the third year "the increase in income is countless." Aquaculture is pitched as a get-rich-quick scheme--just as it is today.

Remarkably, by the time Fan-Li's paean to piscicultural profits came to be written the Chinese had already been practicing aquaculture for 2,000 years, and today China is the world leader, responsible for two-thirds of global production. The industry has come a long way from the rearing of carp in ornamental ponds. Now dozens of freshwater and marine species are farmed, from tilapia to tuna, scallops to seahorses. Geneticists produce superhybrid varieties that are disease-resistant and have faster growth rates, higher nutritional value, shorter life cycles (in the case of shellfish), and longer harvest periods (in the case of edible seaweeds) than their wild progenitors. Oceanographers scour the seas for microbes with potential for use as feedstocks, and aquaculture entrepreneurs design multistory "pondominiums" -- whole cities of sea creatures.

Shrimp aquaculture (more accurately called mariculture, because most farmed shrimp are marine species) has a somewhat shorter history. It was not until the early 1960s that Japanese ichthyologist Motosaku Fujinaga, after 30 years of painstaking research and experimentation, succeeded in raising commercial quantities of the esteemed kuruma sushi shrimp, Penaeus japonicus, in captivity. Word of the breakthrough spread quickly, and Fujinaga's success was followed by further breakthroughs in hatchery techniques, feeding, and disease control. By the 1970s, farmed shrimp -- "pink gold" -- was the star of the Blue Revolution, the anticipated great leap forward in aquatic productivity that many hoped would rival the Green Revolution's surge in grain yields in the 1950s.