A Chilean boat carries dead fish, victims of infectious salmon anemia.

By ALEXEI BARRIONUEVO

RIO DE JANEIRO - With a deadly virus threatening its fish farms, Chile has introduced measures to improve the sanitary conditions of its salmon industry and reduce the levels of antibiotics used to treat the fish.
Chile exports more salmon to the United States than to any other country besides Japan, but it has drawn sharp criticism from environmentalists and other experts in recent months as a virus has killed millions of its salmon.
The illness, infectious salmon anemia, or I.S.A., continues to spread, underscoring how the crowded conditions of Chile’s fish farms and other sanitary concerns are giving rise to a variety of fungal and bacterial fish ailments.
Environmentalists and industry officials applauded the Chilean government’s efforts to clean up the industry and reduce antibiotic use.
Hugo Lavados, Chile’s economy minister, said that after almost four months of study, a government panel identified steps that would ease conditions in crowded salmon pens and provide greater protection against the introduction of high-risk illnesses in salmon eggs. The economy minister also noted that the “intensive” use of antibiotics, although legal in Chile, needed to change and that a specific plan for lowering levels would be finalized by December.
“This is a step in the right direction,” said Dr. Felipe C. Cabello, a professor in the Department of Microbiology and Immunology at New York Medical College in Valhalla who has studied Chile’s fishing industry. Dr. Cabello has said that Chilean salmon producers are using an estimated 70 to 300 times more antibiotics to produce one metric ton of salmon in Chile than are their counterparts in Norway.
He has been the subject of repeated attacks by Chile’s salmon industry for making those claims.
Alex Munoz, vice president for South America for Oceanos, a group seeking to protect marine environments, said, “Unsafe use of antibiotics in salmon pens threatens Chile’s oceans and access to the U.S. seafood market.” He argued that the misguided use of antibiotics could increase bacterial resistance to them. “We are pleased to see the Chilean government act.”
The virus is affecting 2 percent of Chile’s salmon farms, according to SalmonChile, an industry group. “We need to be aware that the virus will be present in Chile for a long time,” said Rodrigo Infante, the general manager of Salmon-Chile.