With Record Antibiotic Use, Concerns Mount that Chile’s Salmon Farms Are Brewing Superbugs | Oceana
Crowded conditions on salmon farms can promote the spread of disease.
Credit: Daryl Hunt / Creative Commons
Chile’s salmon industry has amped up its use of antibiotics every year since 2010. In 2015, salmon farmers there used 660 grams of antibiotics per metric ton of fish. Norway, in contrast, produces more salmon than Chile but uses far fewer drugs — around 0.17 grams per ton.
Chile’s salmon farmers may use more antibiotics on a per-ton basis than any other player in the meat business. According to a 2015 study, the 2010 global average for hog production — a notoriously drug-dependent industry — used 172 grams per ton of pork.
According to Liesbeth van der Meer, the executive director of Oceana Chile, all of the antibiotics fed to salmon are identical or chemically similar to antibiotics used in human medicine.
Tetracycline, for example, is used to combat ailments as diverse as acne, Lyme disease and gonorrhea. Trimethoprim, an antibiotic classified by the World Health Organization as an “essential medicine,” is a first-line treatment for bladder infections. And quinolones, a family of drugs that include Cipro and Avelox, are broad-spectrum antibiotics that other countries have banned for use in aquaculture.
Creating a monster
The soup of antibiotics in Chile’s salmon pens gives bacteria plenty of opportunity to evolve drug-resistant mutations — and that’s exactly what researchers have found.