Report reveals that Chilean farms use 300 to 600 times more antibiotics than farms in Norway, whose huge salmon farming firms own much of the Chilean industry
by Craig Weatherby
An admission by Chile's Economy Ministry reveals the depths of the infection crisis in the country's offshore salmon farms.
And it underscores the unsustainable, eco-threatening tack that Chile's largely foreign-owned fish farms are taking to overcome a problem caused by conditions typical of industrial salmon farms.
In response to a request by the eco group Oceana, filed under a new information access law, Chile's Economy Ministry revealed that salmon farms there used about 850,000 pounds of antibiotic drugs in 2007 and about 718,000 pounds in 2008.
According to a report in The New York Times, this is “…about 346 times the amount of antibiotics Norway used in 2008 (2,075 pounds), and almost 600 times the amount Norway used in 2007” (Barrionuevo A 2009).
Experts blame unsanitary conditions, including cramped pens, for giving rise to the illnesses, many of which are carried by blood-sucking sea lice attracted to the easy, tightly packed pickings.
Chief among these bacterial infections is one called rickettsia (Piscirickettsia salmonis).
This infectious agent occurs in Pacific king and silver salmon farmed in British Columbia, as well as in the far more numerous farmed Atlantic salmon raised in Norway, Maine, Chile, and Eastern Canada.
One fear is that in addition to sea lice that swarm out from British Columbian salmon farms sited near wild salmon migratory rivers, rickettsia from farmed salmon could become a threat to wild Pacific salmon.
The New York Times article also included this comment from Alex Munoz, South American regional vice president for Oceana:
“The ministry's numbers… show that the Chilean government has placed a higher priority on ensuring the profitability of a business sector than protecting consumers and the nation's ecosystems” (Barrionuevo A 2009).
Chile is the world's second biggest salmon exporter, and its salmon firms have been trying, with limited success, to contain the spread of a virus called infectious salmon anemia (ISA) that is killing millions of farmed fish.
Instead of ISA, the antibiotics are used in Chile to fight rickettsia and other non-viral pathogens and parasites carried by sea lice, which typically inflict lesions susceptible to infection.
Starting last year, some of the biggest U.S. food retailers slashed purchases of Chilean salmon because of concerns about residues of the drugs used to combat these illnesses.
Salmon farmers in Chile note that Norway once used twice the amount of antibiotics that Chile is now using, before developing vaccines to deal with its illnesses.
Disturbingly, about one-third of the antibiotics being used in Chile belong to a family of drugs (quinolones) that are not approved for use by the U.S. Food and Drug Administration.
In 2008, the FDA caught three salmon companies operating in Chile—including a Norwegian firm—using unapproved drugs.
- Barrionuevo A. Chile's Antibiotics Use on Salmon Farms Dwarfs That of a Top Rival's. The New York Times, July 27, 2009. Accessed online at http://www.nytimes.com/2009/07/27/world/americas/27salmon.html
- Branson EJ, Nieto Diaz-Munoz D. Description of a new disease condition occurring in farmed coho salmon, Oncorhynchus kisutch (Walbaum), in South America. Journal of Fish Diseases 1991;14:147-56.
- Brocklebank JR, Speare DJ, Armstrong RD, Evelyn TPT. Septicemia suspected to be caused by a rickettsia-like agent in farmed Atlantic salmon. Can Vet J 1992;33:407-8.
- Evelyn TPT. Salmonid rickettsial septicemia. In: Kent ML, editor) Diseases of seawater netpen-reared salmonid fishes in the Pacific Northwest. Canadian special Publication Fish Aquatic Science 116. Nanaimo (BC): Department Fisheries and Oceans 1992;18-9.