As if links to slavery and environmental ills weren't enough to sully the shrimp's reputation, now this favourite ocean crustacean is all mixed up in seafood fraud, too.

Today, Oceana, the largest international advocacy group dedicated to marine conservation, released a report showing that almost a third of shrimp samples (called prawns in the UK) taken from over 100 sources in the United States were misrepresented by origin, fishing method, or species. Oceana is the same group that last year released the investigation into seafood fraud and revealed that one-third of US finfish are labelled as the wrong species.

The new focus on shrimp makes sense, since it's not only the most traded seafood worldwide, but also the most commonly consumed in the US, the report says. "We eat over one billion pounds of shrimp [annually in the US]," says Kimberly Warner, senior scientist at Oceana, and lead author on the report.

The crustacean is already associated with dire human rights violations in parts of Asia, where the fishing industry is one of the largest providers of shrimp to the US, but has also been charged with human trafficking and abuses tantamount to slavery. Ecologically speaking, fishing for wild shrimp typically involves destructive bottom trawling and nets that catch marine life indiscriminately, while the majority of shrimp aquaculture is known for polluting the coastal habitats it inhabits, including delicate mangroves.

Yet despite this turbulent back story, plus the fact that the US imports 91% of its seafood and most of its shrimp, these crustaceans typically don't carry detailed labeling in America. Some big supermarkets are meant to label shrimp according to source, but species descriptions for the majority of shrimp sold in the country are not a requirement. "For 41 species that are known to be sold in the US, it's fine just to call them 'shrimp'," which paves the way for misrepresentation, Warner says.

Oceana found that of the products they sampled from 111 places nationwide – a range of restaurants and grocery shops – 30% were either being presented as another species (noticeably in cases where one could be switched up to a more expensive species like royal red and rock shrimp), were marketed as 'wild-caught' or Gulf shrimp when they hailed from farms in reality, or displayed no country of origin. Some samples were a complete enigma, displaying neither their origin, species, nor information about whether they were farmed or wild.

Unexpectedly, some of the shrimp that were identified in the survey were genetically unknown to science, and one sample taken from a bag of frozen seafood even turned out to be a banded coral shrimp – a species renowned on reefs and coveted as a 'pet' shrimp by aquarium enthusiasts, but certainly not as food. "It's one of the things you look for on a reef," Warner says. "How it ended up in a bag of salad-size shrimp, I have no idea."

The worst rates of misrepresentation were in New York City, where 43% of samples were hazily labeled. More than half of those were called 'wild-caught' when they were, in fact, a common farmed species known as whiteleg.

Oceana's senior scientist Dr. Kimberly Warner examines a shrimp sample during the investigation. Image credit: Oceana

This mislabeling dilemma strips consumers of their ability to make informed and ethical decisions, Warner says. "Without traceability, it is difficult for seafood buyers to be assured that they are not selecting shrimp that are affected by human rights abuses or the illegal fish trade."

Mislabeling by species or origin could also give false impressions about the availability of particular kinds of shrimp. When Oceana took samples for the survey in 2013, less wild shrimp was fished from the Gulf because of a three-year low in the natural stock, Warner says. And yet representing farmed fish as 'wild-caught' or 'Gulf', as was commonly found to be the case, gives the opposite impression. "Certainly if you're selling a Gulf product that's not a wild product, you're giving the sense that it's more available than it is," Warner says. Consequently, consumers might not think to reign in their consumption.

"An immediate fix would be traceability and better labeling, allowing people to choose their seafood confidently and responsibly," she adds, something the presidential task force specifically assembled this year to root out illegal fishing and seafood fraud is well-placed to do. But shrimp lovers should pick a position too. "I think it matters quite a bit what the consumer asks for and expects… if that consumer asks questions about what it is, where it came from, and whether it's traceable."

Eating shrimp is ingrained in American culture, as New York Times writer Kim Severson emphasises in her article about this crustacean. She notes that shrimp has transitioned from a delicacy, to the staple at a feast, and that this has its problems:

We are a popcorn shrimp nation, enthralled by endless shrimp platters and bulging all-you-can-eat seafood buffets. We are lovers of overstuffed po'boys, steaming bowls of scampi and takeout containers dripping with kung pao. Loving shrimp is not a bad thing, but increasingly cooks and environmentalists wonder if we love shrimp too much. Or if we are loving the right shrimp.

As the pounds keep rolling in in their billions, making people aware of what's coming in, and where from, seems like a good way to start tackling that dilemma.