How seafood sleuths are fighting fish fraud

Forty percent of seafood in Canada is mislabelled — so an ocean-conservation group enlisted citizen scientists to combat the problem
By Tina Knezevic - Published on July 26, 2018
Canadian Food Inspection Agency rules were designed to deal with food recalls, not provide traceability information to consumers. (



The fact that seafood is often mislabelled or misrepresented in grocery stores and restaurants may not be news to many Canadians. Over the past few years, seafood fraud has emerged as a global problem — and studies show that roughly 40 per cent of seafood is mislabelled in this country. This doesn’t simply mean we’re often tricked into buying lower-quality fish: such fraud also puts us at risk of consuming harmful contaminants and of unwittingly supporting a black-market trade in endangered species that encourages human-rights violations.

Seafood has a long, complex supply chain. According to Josh Laughren, the executive director of Oceana Canada, an ocean-conservation NGO, food labelling is managed primarily by the Canadian Food Inspection Agency. Suppliers can usually identify the last person they got the fish from, but they don’t generally know where it originated, as CFIA rules were designed to deal with food recalls, not provide traceability information to consumers. This means that consumers — and even grocery stores and restaurants — can have a hard time figuring out where their seafood comes from. While mislabelling is sometimes intentional, it can also happen accidentally as products change hands.

In 2017, Oceana conducted a round of DNA testing in Ottawa to assess the scope of the problem: it found that almost half of the seafood it analyzed had been mislabelled. This year, it extended the opportunity for testing to citizen scientists. “We got 100 volunteers in each of the three cities: Halifax, Vancouver, and Toronto,” Laughren says. (Testing is now complete, and a national report is slated for publication in August.) The program was launched to increase Oceana’s sample size, provide more information about mislabelling rates, and help isolate regional differences across the country. But, perhaps more important, it was intended to reach people beyond the established research community. The organization’s hope is that an informed and engaged public would demand action from government — the only thing, it feels, that could put an end to seafood fraud.

So in April, I signed up to become a so-called seafood sleuth. I’d be collecting samples of fish from local stores or restaurants and then sending them to a laboratory for analysis. Scientists would use DNA barcoding to identify the samples and add them to a growing species database (the International Barcode of Life — a sort of DNA library) that’s been used to support a number of initiatives, including the tracking of seafood fraud.

I purchased my samples at two Toronto locations. Using Oceana’s list of suggested species, I ordered a white tuna roll from a sushi restaurant and some fresh Ontario pickerel from an organic grocery store. (I’m not naming either vendor, because, as Laughren told me, most aren’t aware that they might be selling mislabelled seafood.)

At home, I followed the instructions on my LifeScanner DNA testing kit: I took photos of my fish, cut a tiny piece from each, placed them in their respective test tubes, registered my kit online, and then mailed the samples to a lab at the University of Guelph. I ate the sushi roll for dinner and cooked up the pickerel the next day for lunch.

White tuna is one of the more commonly mislabelled fish. What you often find in its place is escolar, a deep-dwelling fish that’s a bycatch of tuna and can be legally imported into Canada. It sounds much less appetizing when referred to by its nickname: the laxative of the sea (escolar contains high amounts of an oily substance called gempylotoxin, which humans are unable to digest). According to Oceana, escolar can cause “acute gastrointestinal symptoms such as diarrhea, vomiting, and nausea.” I wondered about the white fish working its way to the lab and through my GI tract.

A few weeks later, I had my answers.

The first sample came back as Sander vitreus, or pickerel.

The second sample? Lepidocybium flavobrunneum. It had, in fact, been escolar that had graced my dinner plate a few weeks earlier. I had been duped, but there was no one to get angry at. It’s entirely possible that the sushi chef hadn’t known he’d been serving up the marine aperient.

There are ways that business owners can increase their oversight. Dan Donovan, co-owner of Hooked Inc., a sustainable fishmonger in Toronto, works with an external auditor who verifies the integrity of the supply chain for packaged products (e.g., shrimp) that are caught and processed offshore. When it comes to fresh fish, the company purchases them whole (the species is easier to identify that way), directly from the vessel. The fish is then transported straight from shore to store, minimizing the risk of its being mislabelled in transit. But, even then, Donovan says, labelling isn’t as simple as it sounds. The CFIA Fish List often accepts several common names for each scientific name. Sander vitreus, for example, is not known only as pickerel — it can also be referred to as walleye, walleye pike, and yellow pickerel.

Oceana believes that Canada should be doing more when it comes to seafood labelling. Since January 2018, the United States has required that high-priority imported species be traceable to the point of harvest; the European Union’s consumer-facing policies (considered the gold standard) ensure that fish labels include the species name, the production method, and even the fishing gear used. Ironically, then, Laughren says, in order to access these foreign markets, Canadian companies must ensure that the seafood they export follows strict traceability rules — while those companies that have to adhere to stringent rules at home can relax their standards when selling to Canada. “We call it reverse protectionism,” he says.

And while he knows that not all mislabelling is malicious, he adds, “I have yet to see, I think, a single instance where an expensive fish was substituted for a cheaper one.”

Tina Knezevic is a Toronto-based journalist whose work has appeared in The Walrus and on

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