It seems something fishy is going on in Calgary with the labelling of some sushi products.

An informal research project at the University of Calgary turned up some surprising results — 39 per cent of the fish products sampled were not what they claimed to be.

'Most surprising — shocking actually — were the four salmon sushi samples that were identified by BOLD as rainbow trout.' - graduate student Matthew Morris

Sean Rogers, an associate professor in biological sciences, is quick to point out the sample size for the project was small.

Undergrad students tested the DNA of 18 product samples to see if the fish they were eating was really as advertised.

"Because, when you look at a fish fillet, it's really hard to tell what kind of fish it is," said Rogers.

His students found that seven of the 18 samples had been mislabelled. One test found fish billed as salmon was really trout, and another found red snapper was actually tilapia.

The students used the Barcode of Life Data Systems (BOLD) to help identify the species.

Mistaken identity?

“Most surprising — shocking actually — were the four salmon sushi samples that were identified by BOLD as rainbow trout,” said graduate student Matthew Morris in a release. “These products were collected on different days and from two different locations so we know different individual fish were likely being sampled."

Fish products mislabelled

An undergraduate research project in an ecology course has revealed that some consumers of fish in Calgary are not eating what they thought they were eating. (CBC)

Fourth generation fish monger Bryan Fallwell from the Billingsgate Fish Market doesn't believe restaurateurs are deliberately trying to trick their customers.

Instead he believes this to be a case of mistaken identity. 

"I really don't believe there's any malice involved," said Fallwell.

Billingsgate says the only real way to correctly label and identify fish is if everyone used the same language.

But Rogers says he hopes the undergrad study will be a starting point for a future investigation.

“Mislabelling has widespread implications — to the pocketbook if cheaper fish is mislabelled as more expensive, to health if someone has allergies. And from a conservation perspective, endangered species can be put at additional risk," he said.

"These results were unexpected, frankly, but in alignment with similar studies. The bottom line is fish consumers should be aware that mislabelling is an issue and ask questions about the products they’re buying.”

With files from CBC's Maureen Miller