This post has been updated with a response from the National Fisheries Institute trade group and with a chart detailing Consumer Reports’ findings.
If you’re one of many people who eat shrimp regularly, this may give you pause: A new study by Consumer Reports found that 60% of the raw shrimp that it tested was tainted with bacteria, including some with a dangerous, drug-resistant strain.
Most shrimp is farmed in exporting countries like Thailand, Vietnam, India, and Indonesia, which provide 94% of the US supply. And conditions are pretty gross: If ponds aren’t properly managed, ”a sludge of fecal matter, chemicals and excess food can build up and decay,” Consumer Reports said in its study, “How Safe is Your Shrimp?” Shrimp are often given heavy doses of antibiotics to ward off bacteria and algae that thrive in their crowded tanks and ponds.
Shrimp exports from the three biggest exporters—Thailand, Vietnam and China—have suffered in recent years due to an outbreak of early mortality syndrome (EMS), a bacterial disease, which has hurt restaurant chains like Red Lobster.
Consumer Reports tested 342 frozen samples purchased from supermarkets and other food retailers in 27 US cities. Sixty percent were contaminated with bacteria like salmonella, E. coli, and listeria. Two percent of the samples tested positive for the superbug MRSA (Methicillin-resistant Staphylococcus aureus), a scary strain of drug-resistant bacteria that causes hard-to-treat, life-threatening infections. Three percent of samples had illegally high levels of antibiotic residue.
Raw, farmed shrimp from Bangladesh and India were the most likely to carry bacteria, with 83% and 74% tainted, respectively. Raw, wild-caught shrimp from Argentina and the United States were the least likely to be tainted, at 33% and 20%, respectively.
Harmful bacteria can be neutralized if shrimp are cooked properly—though they can still contaminate other food if they are not prepared carefully. And finding that 60% of shrimp had some levels of bacteria pales in comparison to some other foods: a similar Consumer Reports study found 97% of raw chicken contained harmful bacteria.
But the presence of drug-resistant strains suggests that shrimp farms are overusing antibiotics, which can give rise to more dangerous and hard-to-treat superbugs strains.
Shrimp has other problems aside from bacteria and antibiotics. As Quartz has reported, the Thai shrimp industry—the world’s largest—relies largely on forced labor from Burmese migrants to process farmed shrimp. Abuses in so-called “peeling sheds” include violence against workers, human trafficking, child labor, debt bondage, and sexual harassment.
Seafood conservation groups say that opting for wild-caught shrimp is often a safer and more environmentally conscious choice. The problem, however, is that farmed shrimp from Asia is often mislabeled as “wild” or “Gulf” when it is sold in US stores and restaurants.
The National Fisheries Institute, a trade association for the US seafood industry, tells Quartz that Consumer Reports’ “perspective in various sections of the report raises questions about whether they were simply looking for problems they couldn’t substantiate but reported on them anyway. The fact is shrimp; imported, domestic, farmed or wild is a healthy part of a balanced diet despite the hand wringing and hyperbole we see in this report.”