Defeating seafood fraud, atom by atom

The seafood industry is vulnerable to fraud: how can you be sure your seafood is coming from the place it’s supposed to?

At the moment, the industry is reliant on digital and paper-based tracing. But thanks to new research, we now know a chemical signature that can tell us more about the origins of seafood.

Dr Zoe Doubleday, a marine ecologist at the University of South Australia, says it is important we know where our seafood comes from and that consumers can trust the label of origin.

“Otherwise it threatens the integrity of the industry and the fisheries they depend upon,” Doubleday says.

 The problem with fish substitution also affects restaurants and our health

And more. “This substitution threatens our food system by risking sustainability, safety, and consumer confidence,” adds lead author Dr Jasmin Martino, a former postdoctoral researcher at UniSA now at the Australian Nuclear Science and Technology Organisation.

 “In the long term, it leads to over-exploitation of stocks and upsets the balance of marine ecosystems, ultimately harming seafood industries.”

Read more: Catching fishy imports to tackle seafood fraud

The research, published in Fish and Fisheries, centres around isotopes: atoms of the same element which have slightly different masses, giving them slightly different physical properties.

Heavier oxygen atoms, for instance, will behave slightly differently in rainfall to lighter atoms. This means that the world’s oceans have differing concentrations of oxygen isotopes.

This difference in concentration passes into the bones and shells of seafood.

“Precise levels of chemicals found in seafood is controlled by the ocean where marine life is based, so we can establish a chemical fingerprint that tells us which body of water the animal comes from,” says Doubleday.

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The researchers mapped oxygen isotopes in seafood bones and shells around the world.

They could then use this chemical map to identify the origins of a broad range of seafood.

While it’s not a particularly high-resolution tool at the moment, the researchers say in their paper that it could be further refined with more isotope markers, or possibly DNA analysis, to tailor it to specific species.

“The advantage of chemical fingerprinting is that it is difficult to falsify,” says Doubleday.

“Now that we have established a universal chemical marker, with ongoing research and development, it could transform the way we provenance seafood on a global scale.”

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