While controversy over horsemeat in the European beef and pork supply has captivated people around the world, food experts say Canadian consumers are blasé about mislabelled seafood in North America.

DNA analysis shows 33 per cent of fish sold in grocery stores, restaurants and sushi venues in the U.S. is mislabelled, according to a recent study conducted at the Biodiversity Institute of Ontario (BIO) at the University of Guelph.

The result is consistent with a 2011 study by BIO that looked at samples from five Canadian cities, including Vancouver, Toronto, Gatineau, Que., Montreal and Quebec City and found that 41 per cent of fish was mislabelled.

The latest study of U.S. fish samples, commissioned by the ocean conservation group Oceana, found inferior farmed fish are often substituted for more expensive species. For instance, pangasius is often sold as grouper, sole and cod; tilapia as red snapper; and Atlantic farmed salmon as wild or king salmon.

3 questions to ask when buying fish Mike Nagy suggests consumers ask retailers the following questions before buying fish: Is the fish wild or farmed?

What country does it come from?

How was it caught? If sellers can’t answers these questions about a given fish, "you shouldn't be eating it," Nagy said.

Dirk Steinke, BIO's director of education and outreach who conducted the 2011 study and helped interpret the results of the latest U.S. sample tests, said he was "a little amused" by Canadian consumers' lukewarm response.

"Of course the Americans were very shocked. I saw a few reactions from close by in B.C., where people said in Canada that won't be the case. Knowing that in Vancouver we found the same rate [of mislabelling], I'm a little surprised to hear that," he said.

Among the recent study’s key findings:

Red snapper and tuna are the most frequently mislabelled species (87 and 59 per cent, respectively).

Only seven of the 120 red snapper samples tested correctly.

84 per cent of white tuna samples were actually escolar, which can cause digestive issues for some people.

Mike Nagy, a sustainable food systems consultant in Ontario, said that consumers seldom tolerate fraudulent labelling of land-based food like beef, but there is less diligence when it comes to seafood.

"Somehow in our psyche, especially in Central Canada where we are not tied to the coast, seafood is sort of off our radar," he told CBC Radio’s The Current.

According to Nagy, consumers who fall for seafood mislabelling are not only paying more for lower-grade items, they might also be buying fish that is unsustainable and carry potential health risks.

The Canadian Food Inspection Agency, which enforces the country’s food labelling laws, was not available for comment.

Learning from "Sushi-gate"

Seafood fraud has garnered the interest of researchers since 2008, when two high school students from New York did a DNA analysis that found a quarter of fish products at Manhattan sushi restaurants and seafood markets were mislabelled.

Steinke said that since "Sushi-gate," there has been no improvement in fish labelling, despite numerous studies that confirmed the global trend.

"I don’t see anybody being punished for mislabelling anything. I don’t see any kind of legislation that actually tracks them down."

Fillet versus whole fish Food experts say that fillets are at a greater risk of fraudulent labelling than whole fish. "It's difficult even for experts to tell … what it is when there's no head on the fish," said sustainable food systems consultant Mike Nagy. "The likelihood of somebody putting the wrong label on a full fish is very little. But if you just go into a regular market, there's tons of fillet. Even the people behind the counter don’t know if it’s the real thing or not," said food researcher Dirk Steinke.

Steinke added that while the horsemeat that somehow managed to show up in the European beef and pork supply is likely an accident that will eventually sort itself out, the rampant seafood fraud is an ongoing global problem.

"It's a systematic way of keeping the entire economy going on the wrong premises," he said.

According to Steinke, the seafood industry's identity crisis is driven largely by the financial pressures on companies having to deal with depleted fish stocks. As a result, they take advantage of the price gap by substituting lower-grade fish for expensive species.

While financial advantage is a factor, the sheer number of transactions from the fishing vessel to the dinner table also complicates the labelling process, Nagy said.

"So you have vast amount of products going through vast amount of hands, and that leaves a lot of room for substitution and fraud," he told CBC News.

‘Difficult to make an informed choice’

Nagy said the problem is made worse by Canada's lax labelling system, which gives buyers little information about the country of origin and the capture method of seafood products.

"It's very difficult to make an informed choice just based on basic product [labelling], let alone whether it's the right product in there or not," he said.

Melanie Joy, a Harvard-educated psychologist and author of Why We Love Dogs, Eat Pigs, and Wear Cows, said she is "curious about the public's reaction" to the latest seafood fraud study.

"What I find interesting is this study doesn't seem to have been as widely disseminated as the horsemeat one," she told CBC News.

She cited "carnism," a belief system that guides us to eat certain animals. She said that the more we identify with an animal, the more likely we are to feel empathy for it and the less likely we are to want to eat it.

"It’s easier for humans to identify with mammals, for example, than it is to identify with fish. It's more difficult to perceive the suffering of fish and other aquatic life," she said.

"The idea of eating horsemeat causes a stronger moral reaction and therefore a stronger level of disgust."