By now, we all know about the overuse of antibiotics in animal agriculture and the toll it’s taken on human drugs’ effectiveness. Antibiotic-resistant diseases could cause 10 million deaths each year by 2050, according to an April 2019 new report from the United Nations Ad hoc Interagency Coordinating Group on Antimicrobial Resistance. Luckily, awareness — and pressure — from U.S. consumer and public health officials has led to a 43 percent reduction in these drugs’ use in America’s food production from 2015 to 2017, according to the most recent report from the FDA.
Great news, right? Yes — except the farmers of seafood are just starting to address this problem. Last month, the Chilean salmon industry pledged to reduce its antibiotics usage 50 percent by 2025. That’s an excellent start, and here’s why it matters.
Few consumers are aware that intensive fish-farming operations use (some would say abuse) antibiotics for similar reasons as their land-based counterparts, and with similarly dire potential consequences. Getting a handle on the scope of this problem is harder, because it’s mostly happening outside the United States: NOAA fisheries estimates that the U.S. imports more than 80 percent of the seafood we eat, and that about half of this imported seafood is farmed.
The amount of antibiotics used in aquaculture globally remains difficult to track. While some parts of the industry, such as Norway, have significantly reduced the amount of antimicrobials used, elsewhere prophylactic antibiotic use remains widespread and unregulated.
Open Water or Closed Containment: Neither are Immune from Trouble
There are several types of aquaculture operations — land based, coastal, and deep water. All three tend to use some form of antibiotics, most of which are medically important for humans.
Coastal open-water operations have come under fire for polluting coastal ecosystems with effluent and chemicals, including antibiotics, among a host of other issues. Deep-water open-ocean operations, which are farther offshore, may have fewer issues with pollution because of strong open water currents that will disperse waste. But the jury’s still out on that. Studies have found that a significant amount of antibiotics — approximately 80 percent — administered in pellet feed are released into the aquatic environment via urine and feces and in unconsumed food. Not good for the health of our ecosystems.
And, the overuse of antibiotics in aquaculture is “contributing to the same resistance issues established by terrestrial agriculture,” according to a 2015 study published in The American Association of Pharmaceutical Scientists Journal. This means the dread superbugs, or bacteria that should be killed by antibiotics, but through continued exposure have instead evolved and gotten stronger. We also don’t know yet how constant antibiotics bombardment is affecting important beneficial bacterial plankton and algae in the coastal and ocean environments.
Self-contained land-based farms are better from a collateral-damage standpoint, because compared to open-water operations, they are by their nature more isolated: they clean and recirculate the water they use. There is less risk of introducing pathogens into the farm, which also means there’s typically a reduced need for antimicrobials. These systems also typically don’t discharge active chemicals or byproducts (like antibiotic-resistant bacteria) into the environment.
But what about antibiotic-resistant bacteria that travel home on an aquaculture facility worker’s clothes? Superbugs are hitching rides home from hog farms on workers. And what happens when untreated wastewater does get accidentally discharged into the environment, from say, a hurricane?
Put A Label On It
Now that I’ve scared you, you’re going to ask me what labels to look for in the seafood case. Alas, there isn’t an easy answer — yet.
While the Certified Organic label for land-based animals forbids the use of antibiotics, there is currently no USDA Organic standard for aquaculture, although the agency is working on one. (You may have seen salmon from Scotland or British Columbia labeled “organic” in the grocery or online. Both Canada and the European Union have developed organic standards for seafood, but the standards aren’t the same as USDA standards. Canada’s forbids antibiotics, while the E.U.’s do not.) The Monterey Bay Aquarium’s Seafood Watch criteria, the Global Aquaculture Alliance’s Best Aquaculture Practices standards, and the Aquaculture Stewardship Council’s standards all incorporate the use of chemicals (including antimicrobials, the parent class of antibiotics) into their criteria for evaluating aquaculture operations, but don’t break them out separately.
When asked about antibiotics reporting, aquaculturists are quick to offer results from antibiotics residue testing. This measures whether or not there is a presence of the drug left in the edible fish, not how much antibiotics were used (or for what purpose), nor if antibiotic-resistant bacteria remain in the environment or on the fish.
Without transparency, neither home cooks nor large purchasers can easily support aquaculture operations that are using less antibiotics than their peers. By remaining under the radar, aquaculture has avoided the consumer pressure felt by terrestrial farming operations. I recently wrapped up a long research project with the Center for a Livable Future to set a new purchasing standard for responsible antibiotics for the company I work for, a large buyer of seafood. Our stated preference is to buy meat, poultry, and seafood raised without the use of antimicrobials, except where necessary to treat sick animals in the documented presence of disease in the flock, herd, or fish population as verified by a veterinarian. We know where we stand antibiotics-wise with our meat from land-based animals. However, due to the lack of transparency in the global seafood supply chain, and the lack of reporting on antibiotics usage by aquaculture producers, we’re at sea when it comes to farmed fish.
Let’s be clear, I’m not advocating to ban antibiotics in aquaculture. As on land, they can have an important part to play in animal health and welfare. We need better reporting and better labeling so consumers can distinguish who is using them responsibly, and vote for better practices with their wallets. The Chilean salmon farmers are taking a step in the right direction. Let’s hope the rest of the industry — and the world — follows.
