And You Thought You Liked Shrimp

If you picked the first, stop reading now.

The world shrimp catch has tripled since 1970. It's now 50 percent beyond what the UN Food and Agriculture Organization figures is the long-term sustainable limit. In several countries shrimp fisheries are using more and more boats to bring in the same quantity of shrimp. These overextended fisheries continue only because, like failing fisheries everywhere, they are subsidized by governments.

It would be a boon to other fisheries to let shrimping collapse, because on average for every pound of shrimp brought up in nets five pounds of other creatures come up as "bycatch" and are thrown back dead. The bycatch includes bass, herring, crab, mullet, flounder and tuna, often juvenile, as well as ancient, endangered sea turtles. U.S. shrimpers are required to fix their nets so turtles can get out, but that doesn't help the rest of the bycatch or the turtles in the rest of the world. Shrimp bycatch totals 19 million pounds a year, 20 percent as much as the world's total commercial fish catch.

As the ocean fisheries decline, shrimp aquaculture is rising. It now supplies one-fourth of all shrimp consumed, half of all shrimp entering international trade. Shrimp farming has been practiced in a low-key way for a long time. When low-lying coastal land in the tropics gets inundated by storm surges or high tides, farmers sometimes discover that their fields are full of shrimp. Some increase the bonanza by making small dams to hold back floodwater for awhile or by pumping seawater in.

Modern shrimp farming takes that simple process and turns it into a watery equivalent of modern chicken farming. Intensive shrimp farms consist of bulldozed, uniform ponds seeded with superdense populations of shrimp fed with carefully formulated feed.

Like chickens but even more so, shrimp raised in close quarters get diseases. The ponds must be treated with antibiotics and disinfectants, also with pesticides to eliminate predators and competitors. Here is a partial list of chemicals used in shrimp aquaculture: copper sulfate, sodium hypochlorite, potassium cyanide, tobacco dust, malathion, aldrin, DDT, terramycin, streptomycin, tetracycline. These chemicals are released into nearby waters when the ponds are flushed, and they can contaminate the shrimp.

In spite of the chemicals, shrimp aquaculture is so new that it doesn't work very well. No one has succeeded in breeding shrimp continuously; new spawn must be brought in from the wild. All the major shrimp-farming countries (Thailand, Indonesia, China, Ecuador, India) have experienced widespread epidemics in the ponds. Growers harvest shrimp at less valuable smaller sizes, to get them to market before they get sick. (The big shrimp you see are wild-caught.) On average a shrimp pond lasts five years before it is too contaminated to use.

Therefore the intensive shrimp farmers stay mobile, sweeping in with large amounts of money, buying up and flooding farms and villages, extracting breathtaking profits (40-50 percent per year return on investment) for a few years, and moving on, leaving the local population with salty, barren land that can't be used for shrimp, rice, or anything else. (The farms are too recently abandoned to know yet how long it will take them to recover.)

Unfortunately it's convenient to put shrimp ponds where mangroves grow. Mangroves, half-submerged coastal forests, teeming with life, are nurseries for many kinds of sea creatures, including shrimp. Thailand has lost at least 150,000 acres of mangroves to shrimp farming (and still more to coastal development and charcoal burners). Thai shrimp farms, which for the moment export $2 billion worth of shrimp a year, have already moved from the north central gulf to the east coast to the southeast coast, crashing each time from disease and water pollution. They are now moving to the Andaman coast, where 80 percent of Thailand's remaining mangroves are located.

The real culprits are the greedy shrimp fishers and farmers, right? Or the Japanese and Taiwanese investors who are raking off the huge profits? Or the corrupt governments that subsidize the industry and help big exporters take away small peasants' coastal lands? Or the Darden Restaurant chain, owner of Red Lobster, which imports half the shrimp that comes into America? Or the happy, heedless folks who flock in for the cheap all-you-can-eat shrimp special? Or everyone in human history who has had more than two children and helped to swell the population?

Blame is not a useful exercise, folks. Seems to me what we need is worldwide regulation of the shrimp industry, so it doesn't wipe itself out.

I'm indebted to Jason Clay of the World Wildlife Fund for much of the research summarized in this column.