AGUA AZUL, Honduras — A common Bible story says Jesus fed 5,000 people with five loaves and two fish, which scholars think were tilapia. (Tilapia is a form of fish)
But at the Aquafinca fish farm here, a modern miracle takes place daily: Tens of thousands of beefy, flapping tilapia are hauled out of teeming cages on Lake Yojoa, converted to fillets in a cold slaughterhouse and rushed onto planes bound for the United States, where some will appear on plates within 12 hours.
Americans ate 475 million pounds of tilapia last year, four times the amount a decade ago, making this once obscure African native the most popular farmed fish in the United States. Although wild fish dominate in most species, a vast majority of the tilapia consumed in the United States is raised from pens or cages in Latin America and Asia.
Known in the food business as “aquatic chicken” because it breeds easily and tastes bland, tilapia is the perfect factory fish; it happily eats pellets made largely of corn and soy and gains weight rapidly, easily converting a diet that resembles cheap chicken feed into low-cost seafood.
“Ten years ago no one had heard of it; now everyone wants it because it doesn’t have a fishy taste, especially hospitals and schools,” said Orlando Delgado, general manager of Aquafinca.
Farmed tilapia is promoted as good for your health and for the environment at a time when many seafood supplies have been seriously disappearing. “Did you know the American Heart Association recommends eating fish twice a week?” asks the industry Web site, abouttilapia.com. But tilapia has both nutritional and environmental drawbacks.
Environmentalists argue that intensive and unregulated tilapia farming is damaging ecosystems in poor countries with practices generally prohibited in the United States — like breeding huge numbers of fish in cages in natural lakes, where fish waste pollutes the water.
“We wouldn’t allow tilapia to be farmed in the United States the way they are farmed here, so why are we willing to eat them?” said Dr. Jeffrey McCrary, an American fish biologist who works in Nicaragua. “We are exporting the environmental damage caused by our appetites.”
Defenders of tilapia aquaculture point out that this young and rapidly growing industry has begun improving standards and toughening regulation. The two-year-old Aquaculture Stewardship Council, the brainchild of the conservation organization WWF and I.D.H., a Dutch sustainable trade program, is rolling out an inspection program for tilapia farms independent of the industry. Those that choose to participate — and pass — will receive labels identifying their product as “responsibly farmed.”
From Africa to the World
Tilapia is native to lakes in Africa, this versatile warm-water fish was deployed by many governments in poor tropical countries around the world in the second half of the 20th century to control weeds and mosquitoes in lakes and rivers. In a cistern or pond, a few fish yielded dietary protein.
Today, wild tilapia has squeezed out native species in lakes throughout the world with its aggressive breeding and feeding.
By the 1990s, businesses saw opportunity in farming this hearty species. Farmed tilapia reaches its sales weight of about two pounds in roughly nine months of intensive feeding.
Last year, more than 52 million pounds of fresh tilapia were exported to the United States, mostly from Latin America, as well as 422 million more pounds of frozen tilapia, both whole and fillet, nearly all from China, according to the United States Department of Agriculture.
For United States shoppers picking up tilapia from China or Honduras or Ecuador, there is little guidance. “It’s such a complicated job for consumers to decide what to eat, with aquaculture production expanding so rapidly,” said Peter Bridson, aquaculture research manager of the Monterey Bay Aquarium, which produces the popular Seafood Watch, an independent consumer guide to buying sustainable fish.
The new sustainability standards being developed for aquaculture will be tailored by species to address their diverse environmental risks. For tilapia, that means fish cages can be placed only in lakes where tilapia already live, and must be designed to prevent escapes. To limit overtaxing of lakes, the new guidelines establish water quality rules for oxygen and phosphorus, a product of fish waste.
Fish farms may not use prophylactic antibiotics. But even the new rules allow for some practices considered unacceptable in the United States, where cage farming in lakes is generally forbidden. In many states, tilapia must be housed in specially designed pens with roofs to prevent birds from carrying the fish elsewhere; their waste is often collected to use as fertilizer rather than released. Also, the new standards allow for baby fish to be fed testosterone even though markets like Whole Foods will not buy hormone-treated seafood
For the moment, Seafood Watch lists tilapia raised in the United States as a “best choice,” tilapia from Latin America as a “good alternative” and tilapia from China as “to be avoided.” Less than 5 percent of the tilapia consumed in the United States is farmed within its borders, and that is mostly whole fish. Dr. Bridson said these rough ratings were largely based on the presence of effective monitoring in those places and how farms disposed of their waste.
The Pollution Problem
But many biologists worry that the big business of tilapia farming will outweigh caution, leaving dead lakes and extinct species.
Dr. McCrary has spent the past decade studying how a small, short-lived tilapia farm degraded Lake Apoyo in Nicaragua. “One small cage screwed up the entire lake — the entire lake!” he said of the farm, which existed from 1995 to 2000.
Waste from the cages polluted the pristine ecosystem, and some tilapia escaped. An aquatic plant called charra, an important food for fish, disappeared, leaving the lake a wasteland. Today, some species of plants and fish are slowly recovering, but others are probably gone forever, said Dr. McCrary, who works for the Nicaraguan foundation FUNDECI.
Although environmentalists long battled to shut down Nicanor, the Nicaraguan fish farm is failing for another reason: cheap frozen tilapia fillets from China.
Imports of frozen tilapia to the United States rose 30 percent in 2010, as fresh fillet imports dropped 2 percent, reducing demand from smaller producers like Nicanor. Much of the fish that China exports is what producers call “refreshed,” which means it is frozen and packed in carbon monoxide to preserve color so it can be thawed and sold in fish displays, where it will appear to have been recently caught. Even in Managua, the capital of Nicaragua, the tilapia on supermarket shelves is from China.
“People wanted to pay $3.99 a pound for this frozen stuff rather than $5.99 for fresh, especially during the recession,” said Mr. Senna, the Nicanor manager. Chinese fish farms are regarded as poorly regulated, Dr. Bridson said, which is why the world needs clearer standards for sustainable fish farming and consumer labeling. Until then, the biggest producer offering the cheapest product is poised to win.
“If I have 100 tilapia in a pond, I may have happy tilapia because they have room to swim, but I won’t be able to sell them since I won’t get access to the global market,” Dr. McCrary said, adding that, for now, “there’s no tilapia equivalent of free-range chicken.”