jueves, 15 de enero de 2009

THE BLUE REVOLUTION





Blue Revolution
by Marguerite Holloway, Photography by Kristine Larsen
published online September 1, 2002


View through an underwater camera used by technicians monitoring the release of food pellets at a salmon farm near Vancouver. About 50 percent of the protein in the pellets comes from fish meal and fish oil. "Farms are getting more efficient in controlling the amount of feed expended per fish," says aquaculture expert Rosamond Naylor. "But as the industry expands, it will require more wild fish to use as feed for farmed fish."
Last October, Stanford University economist Rosamond Naylor spent four hours flying over the southern part of the state of Sonora, which is half desert, half Sierra Madre mountains, in a crop-dusting plane borrowed for the outing. She was looking for evidence of inland shrimp farms, a burgeoning industry, and expected to find clusters of scattered ponds separated by huge tracts of sere land. Instead, it looked as if the Sea of Cortes had risen and swept across more than 42 square miles of the Sonoran: everywhere patches of blue, pools of shrimp, one after another, all down the coast. "It was so much more developed than I had thought," Naylor says. "The farms are right next to each other."
Over the course of a year, 95 percent of Mexico's farmed shrimp harvest—64 million pounds in 2000—makes its way to the United States. Most of the shrimp Americans consume come from abroad, and chances are excellent that they were farmed in Asia, Central or South America, or Mexico. We are also eating salmon raised on ranches that float in the seas off the coasts of Norway, Chile, Maine, and the Pacific Northwest. Slightly less than one-third of the seafood we consume is not wild at all, according to the U.S. Food and Drug Administration. It comes from aquaculture, a $52-billion-a-year global enterprise involving more than 220 species of fish and shellfish that is growing faster than any other food industry—so fast that fish farming is expected to exceed beef ranching within a decade.
This blue revolution could help solve some big problems. It could provide fish for an ever-growing number of consumers and more food for the 1 billion chronically malnourished people worldwide who need protein. And it could do so while saving rapidly disappearing wild fish by relieving the pressure of commercial fishing. But Naylor is one of a group of scientists and environmentalists who are not convinced that aquaculture is beneficial. She contends that in many places, the practice is destroying land along coasts and causing water pollution. And instead of helping save wild fish, she argues, aquaculture may actually be hastening their demise. "To say that aquaculture shouldn't happen at all would be wrong," she says. "But right now aquaculture is a slash-and-burn activity, shrimp farming in particular."
(A) A typical shrimp farm in the southern Sonoran Desert of Mexico covers nearly 250 acres. (B) Four-month-old shrimp will be harvested within another two months. (C) "Disease can spread quickly between closely linked ponds," says Naylor, on a tour with locals who fish for shrimp the old-fashioned way.
Naylor is convinced that these improvements could help the blue revolution succeed in areas where the green revolution failed. Given the diversity and global character of the industry, she has set her sights high. But consider this: She has seen a desert turn first green and now blue, and she has seen crustaceans swimming amid cacti. In the light of such wonders, anything seems possible.
Goldburg, Rebecca J., et al. "Marine Aquaculture in the United States: Environmental Impacts and Policy Options." Pew Oceans Commission, Arlington, Va., 2001. Available online at
www.pewoceans.org/oceanfacts/2002/01/11/fact_22988.asp.

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