Looking out over the low green mountains jutting through miles of placid waterways here in southern Chile, it is hard to imagine that anything could be amiss. But beneath the rows of neatly laid netting around the fish farms just off the shore, the salmon are dying.
A virus called infectious salmon anemia
, or I.S.A., is killing millions of salmon destined for export to Japan, Europe and the United States.
It has also opened the companies to fresh charges from biologists and environmentalists who say that the breeding of salmon in crowded underwater pens is contaminating once-pristine waters and producing potentially unhealthy fish.
Some say the industry is raising its fish in ways that court disaster, and producers are coming under new pressure to change their methods to preserve southern Chile’s cobalt blue waters for tourists and other marine life.
“All these problems are related to an underlying lack of sanitary controls,” said Dr. Felipe C. Cabello, a professor in the Department of Microbiology and Immunology at New York Medical College in Valhalla that has studied Chile’s fishing industry. “Parasitic infections, viral infections, fungal infections are all disseminated when the fish are stressed and the centers are too close together.”
But the latest outbreak has occurred after a rash of nonviral illnesses in recent years that the companies acknowledge have led them to use high levels of antibiotics
. Researchers say the practice is widespread in the Chilean industry, which is a mix of international and Chilean producers. Some of those antibiotics, they say, are prohibited for use on animals in the United States.
Many of those salmon still end up in American grocery stores, where about 29 percent of Chilean exports are destined. While fish from China have come under special scrutiny in recent months, here in Chile regulators have yet to form a registry that even tracks the use of the drugs, researchers said.
The new virus is spreading, but it has primarily affected the fish of Marine Harvest, a Norwegian company that is the world’s biggest producer of farm-raised salmon and exports about 20 percent of the salmon that come from Chile.
Salmon produced in Chile by Marine Harvest are sold in Costco and Safeway stores, among other major grocery retailers, said Torben Petersen, the managing director of Marine Harvest here.
Arne Hjeltnes, the main spokesman in Oslo for Marine Harvest, said that his company recognized that antibiotic use was too high in Chile and that fish pens too close together had contributed to the problems. He said Marine Harvest welcomed tougher environmental regulations.
“Some people have advocated that this industry is too good to be true,” Mr. Hjeltnes said. “But as long as everybody has been making lots of money and it has been going very well, there has been no reason to take tough measures.”
He called the current crisis “eye-opening” to the different measures that are needed.
On a recent visit to the port of Castro, about 105 miles south of Puerto Montt, a warehouse contained hundreds of bags, some weighing as much as 2,750 pounds, filled with salmon food and medication.
The bags — many of which were labeled “Marine Harvest” and “medicated food” for the fish — contained antibiotics and pigment as well as hormones to make the fish grow faster, said Adolfo Flores, the port director.
Environmentalists say the salmon are being farmed for export at the expense of almost everything else around. The equivalent of 7 to 11 pounds of fresh fish are required to produce 2 pounds of farmed salmon, according to estimates.
Salmon feces and food pellets are stripping the water of oxygen, killing other marine life and spreading disease, biologists and environmentalists say. Escaped salmon are eating other fish species and have begun invading rivers and lakes as far away as neighboring Argentina, researchers say.
“It is simply not possible to produce fish on an industrial scale in a sustainable way,” said Wolfram Heise, director of the marine conservation program at the Pumalin Project, a private conservation initiative in Chile. “You will never get it into ecological balance.”
When companies began breeding non-native Atlantic salmon here some two decades ago, salmon farming was seen as a godsend for this sparsely populated area of sleepy fishing towns and campgrounds.
The industry has grown eightfold since 1990. Today it employs 53,000 people either directly or indirectly. Marine Harvest runs the world’s largest “closed system” fish-farming operation at Rio Blanco, near Puerto Montt, where 35 million fish a year are raised until they weigh about a third of an ounce.
As the industry abandons the Lakes region in search of uncontaminated waters elsewhere, local residents are angry and worried about their future.
The salmon companies “are robbing us of our wealth,” said Victor Guttierrez, a fisherman from Cochamó, a town ringing the Gulf of Reloncavi, which is dotted with salmon farms. “They bring illnesses and then leave us with the problems.”
Since discovering the virus in Chile last July, Marine Harvest has closed 14 of its 60 centers and announced it would lay off 1,200 workers, or one-quarter of its Chilean operation. Since the company announced last month that it would move south, to Aysén, the government has said the virus has spread there as well, in two outbreaks not involving Marine Harvest.
Industry officials say Chile is suffering growing pains similar to salmon farming operations in Norway, Scotland and the Faroe Islands, where a different form of the I.S.A. virus struck previously.
Norway, the world’s leading salmon producer, eventually decided to spread salmon farms farther apart, reducing stress
on the fish, and responded to criticism of high antibiotic use with stronger regulations and the development of vaccines.
Researchers in Chile say the problems of salmon farming go well beyond the latest virus. Their concerns mirror those of the Organization for Economic Cooperation and Development
in Paris, which heavily criticized Chile’s farm-fishing industry in a 2005 report.
The O.E.C.D. said the industry needed to limit the escapes of about one million salmon a year; control the use of fungicides like green malachite, a carcinogen that was prohibited in 2002; and better regulate the colorant used to make salmon more rosy, which has been associated with retina problems in humans. It also said Chile’s use of antibiotics was “excessive.”
Officials at Sernapesca, Chile’s national fish agency, declined repeated requests for interviews for this article and did not respond to written questions submitted more than a week ago.
But Cesar Barros, the president of SalmonChile, an industry association, said, “We are working with the government to improve the situation.”
He dismissed the broader criticism of sanitary conditions, saying there was no scientific evidence to support the claims. But researchers charge that the industry has been reluctant to pay for scientific studies, which Chile sorely needs.
Residual antibiotics have been detected in Chilean salmon that have been exported to the United States, Canada and Europe, Dr. Cabello said.
He estimated that 70 to 300 times more antibiotics are used by salmon producers in Chile to produce a ton of salmon than in Norway. But no hard data exist to corroborate the estimates, he said, “because there is almost an underground market of antibiotics in Chile for salmon aquaculture.”
Researchers say that some antibiotics that are not allowed in American aquaculture, like flumequine and oxolinic acid, are legal in Chile and may increase antibiotic resistance for people. Last June the United States Food and Drug Administration
blocked the sale of five types of Chinese seafood because of the use of fluoroquinolones and other additives.
But huge numbers of fish go uninspected. The F.D.A. inspected only 1.93 percent of all imported seafood in 2006, Food and Water Watch said, citing F.D.A. data.
Stephanie Kwisnek, a spokeswoman for the F.D.A., said that she did not know the percentage inspected. But she said the F.D.A. tested 40 samples of the 114,320 net tons of salmon imported from Chile in 2007. None of them tested positive for malachite green, oxolinic acid, flumequine, Ivermectin, fluoroquinolones or drug residues, she said.
The F.D.A. is planning an inspection trip to assess Chile’s overall controls on its farmed salmon, she added.
Mr. Petersen, the managing director of Marine Harvest in Chile, said the company planned to return to the Lakes region in a few years, once the area had become free of contamination. In the longer term, he said, Marine Harvest will leave Chile’s fresh-water lakes and produce more older salmon in closed systems where it can maintain “biological control.”
“If the water continues to be contaminated, we will simply have to go to another area to find our fish,” he said. “But it is getting harder and harder.