Socially sustainable seafood requires diligence, scrutinyOctober 18, 2022
In an undergraduate classroom at the University of North Carolina Chapel Hill in 2017, a group of students sat in front of a plate of sushi from a local restaurant. But it wasn’t lunchtime — the students were attempting to quantify how common the mislabeling of red snapper was across North Carolina.
By analyzing the DNA from 43 fish samples they’d collected from seafood markets, grocery stores and restaurants across 10 counties, they found that a whopping 90.7% were mislabeled as red snapper. Most often, the substitutions were tilapia or vermillion snapper.
“It’s really hard to know where the mislabeling is happening, obviously, because a lot of seafood goes through a number of steps; it changes hands like five to seven times,” said Dr. John Bruno, instructor and creator of the class. “So it’s hard to know who’s doing it.”
Bruno was asked by the university to create an undergraduate course that gave first-year students real research experience. The idea was to engage students in science early on, and increase retention and diversity in STEM, or science, technology, engineering and math.
“They’re students that have never held a pipette. They’ve never asked a question, never developed a hypothesis,” Bruno said. “The idea was to develop a question that’s applied, that’s meaningful to them, that they can grasp, and then use that question to teach the basic research techniques.”
According to Bruno, mislabeling — essentially committing fraud — is rampant in the food industry. So diving into the mislabeling of local seafood was something Bruno felt the students could investigate.
Why is mislabeling so widespread? “I think there’s clearly a lack of enforcement and a lack of testing,” Bruno said.
Based on customer demand, certain fish can be sold for more than others. And this may tempt producers into mislabeling their fish when the desired product is out of season or low in availability.
“There’s obviously a big economic incentive to mislabel,” Bruno said.
Red snapper is a great example. It’s been overfished in the Gulf of Mexico and the southeastern Atlantic.
“So there’s very little of it available … yet the public demands it year round just because it’s something we’re familiar with,” Bruno said. “It’s not necessarily spectacularly better than other fish. It’s just culturally in demand.”
There are some fishing operations that allow you to buy seafood straight from the fishers who caught it. But often, seafood found in restaurants and grocery stores has a much longer chain of production. It’s easy for information to get changed along the way, but harder to pin down exactly where the deception is occurring.
In Bruno’s course, students went out to restaurants and grocery stores and collected samples of seafood. The students then extracted the DNA and amplified it using PCR, or…