Global Fish Reveals Its Dark Side*

AGUA AZUL, Honduras - A common Bible story says Jesus fed 5,000 people with five loaves and two fish, which scholars surmise were tilapia.

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 predominate in most species, a vast majority of the tilapia consumed in the United States is "harvested" 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 marine stocks have been seriously depleted. Compared with other fish, farmed tilapia contains relatively small amounts of beneficial omega-3 fatty acids, the fish oils that are the main reasons doctors recommend eating fish frequently; salmon has more than 10 times the amount of tilapia. Also, farmed tilapia contains a less healthful mix of fatty acids because the fish are fed corn and soy instead of lake plants and algae, the diet of wild tilapia.

"It may look like fish and taste like fish but does not have the benefits - it may be detrimental," said Dr. Floyd Chilton, a professor of physiology and pharmacology at Wake Forest Baptist Medical Center who specializes in fish lipids in Winston-Salem, North Carolina.

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.

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." Aquafinca, which began adopting more environmentally friendly cultivation in 2006 to better appeal to large corporate customers like Costco, has became the first to pass an inspection.

Proponents say tilapia aquaculture will only grow in importance because it provides food and jobs in a world of declining fish stocks and rising population. "There are going to be more farmed fish each year," said Kevin Fitzsimmons, a
biologist at the University of Arizona. "Think about it: if we tried to get beef from hunting, there would be a lot of hungry people."

Native to African lakes, this versatile warm-water fish was deployed by many governments in many poor tropical countries around the world in the second half of the 20th century to control weeds and mosquitoes in lakes and rivers. In retrospect, this "maybe was not the best idea," said Aaron McNevin, a biologist for the W.W.F. who is working on coordinating the development of standards for tilapia farms, because tilapia "is one of the most invasive species known and very hard to get rid of once they are establ ished." 

By the 1990s, businesses saw opportunity in farming this hearty species. Using selective breeding, scientists created today's industrial strains: big,fleshy fish with tiny heads and tails, and intestines that al low them to absorb food  faster. Farmed tilapia reaches its sales weight of about a kilogram in roughly nine months of intensive feeding. 

"Nature is for maintaining species; what we do is make fillets," said Danilo Sosa, a technician at the tilapia breeding pens of Nicanor Fish Farms, outside Managua, Nicaragua.

For 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, aquacul ture research manager of the Monterey Bay Aquar ium in Cal i fornia. The aquar ium produces the popular Seafood Watch,an independent consumer guide to buying sustainable fish.

For the moment, Seafood Watch lists tilapia raised in the United States as a "best choice," t i lapia f rom Lat in America as a "good alternative" and tilapia from China as "to be avoided." 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.

But many biologists wor ry that the big business of t i lapia farming wi l l outweigh caution, leaving dead lakes and extinct species.

Dr. Jeffrey McCrary, a fish biologist,has spent the past decade studying how a small, short-lived tilapia farm degraded Lake Apoyo in Nicaragua. "One smallcage 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 foundat ion FUNDECI.

Dr. Salvador Montenegro, director  of Nicaragua's Center for Aquatic Resource Investigation, has spent a decade fighting to close the Nicanor tilapia farm in Lake Nicaragua, saying it "jeopardizes a lake that is a national treasure."
Weaker fish, like the rainbow bass, have been disappearing from the lake.

But David Senna, Nicanor's manager, said the company's cages occupied only a tiny fraction of the lake, in an area with strong currents sufficient to carry away fish waste. He noted that tilapia were introduced to Lake Nicaragua in the 1980s, "so if they're going to take over, it was already doomed."

For doctors, the debate has centered on tilapia's nutritional value. Bruce Holub, a professor of nutritional science at the University of Guelph in Ontario, said tilapia is a source of protein and contains some omega-3. But others are
concerned about research showing that another type of fatty acids, omega-6, outnumber the beneficial omega-3s in
farmed tilapia by 2 to 1. Some research suggests that ratio increases the risk of heart disease.

The Mayo Clinic, an American medical research group, advises patients that tilapia does not "appear to be as heart-healthy."
 
And much of the tilapia on the world's markets comes from China. China ex-ports the fish frozen and packed in car-
bon monoxide to preserve color and appear fresh once thawed for retail sale. "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 manager of Nicanor. Chinese fish farms are regarded as poorly regulated, Dr. Bridson said, which is why the industry 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."