Students uncover fish fraud

Maggie Maclellan
21 December 2012

Do you know what kind of fish you are buying? It says so on the package, right? Not necessarily.

Since September, twenty-three high schools in Ontario and Manitoba have been participating in CurioCity’s Fish Market Survey project and uncovering cases of fish fraud. CurioCity ( is web-based program offered by charitable organization, Let’s Talk Science that enables Grade 8-12 students to explore the science, technology, engineering and math in their lives.

The Fish Market Survey is a co-operative youth action project developed by CurioCity and the Biodiversity Institute of Ontario (BIO) to add to the bank of research associated with fish labeling fraud and to connect high school students with Canadian researchers.

“CurioCity action projects like the Fish Market Survey allow us to bring real-life projects to Canadian high school students and encourage their interaction with Canadian researchers,” said Bonnie Schmidt, President and Founder of Let’s Talk Science. “These types of projects are important for students’ development as they place science in a meaningful context by demonstrating how science affects students’ everyday lives.”

The Fish Market Survey is the first time Canadian teachers have been able to use this type of project in the classroom with curriculum-related educational resources developed by Let’s Talk Science Education Specialists.

For the project, classrooms worked together to collect seafood samples limited to fresh or frozen products. Of the 332 samples collected, 302 generated a DNA barcode sequence. After analyzing the barcode sequence at BIO, the students discovered that 14% of the samples did not match the market name listed.

The chart below outlines some of the anomalies in the samples:

Comparison of Fish Species Name on the Purchased Package

with Species Name from DNA Analysis

Common Fish Name from the Package

Common Fish Name Based on DNA sample


Antarctic Toothfish


Rougheye Rockfish




Dover Sole

TWO separate samples of Tilapia

Mexican River Gizzard Fish

After discovering that fish mislabelling happens, students examined the reasons behind fish fraud. What they found is that not all fraud is the result of evil intent. However, their conclusions exposed some very real issues.

“Consumers are definitely being ripped off,” said Robert Hanner, a biologist at BIO and Associate Director for the Canadian Barcode of Life Network who oversaw the analysis of the DNA samples.

For the purposes of this study, fraud is defined as “false, misleading or deceptive” leading to the buyer not purchasing what they believe they are purchasing. High value species are most subject to substitution. The Red Snapper you think you are buying for $13.90/lb is actually tilapia, a fish of lesser quality and taste that costs $8.25/lb. Another concern is that rare fish are being sold under the guise of a more common species.

So is it time to go to the grocery store and confront the fresh fish section? No. First of all, there are many points in between the waterway and the grocery store where fraud could happen, and secondly, once the fish have been stripped of skin, fins, head, tail and guts, the resulting fillets bear a remarkable likeness to each other. These items, coupled with language barriers and muddled common name usage, make for a convoluted puzzle.

So where is the fraud likely to happen, and is it deliberate or accidental? No one knows. That’s the next step for the students to uncover.

For more information about the CurioCity Fish Market Survey, please visit:

Let’s Talk Science Contact:

Maggie MacLellan

Communications Officer

Let’s Talk Science

1-877-474-4081 ext. 239

About Let’s Talk Science:

Let’s Talk Science is an award-winning, national, charitable, science outreach organization. Let’s Talk Science creates and delivers science learning programs and services that brings science to life for children and youth, keep them engaged in learning and develop their potential to become 21st century citizens, innovators and stewards. For more information about Let’s Talk Science, please visit

Maggie Maclellan

Maggie MacLellan is a Communications Officer with Let's Talk Science.

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