Aussies, Drop That Fish! It May Be Endangered Shark.
It’s a classic meal for any Australian: fish and chips (fries) by the beach, the dual flavors of vinegar and fresh seafood mixing in your mouth as the crashing of the ocean waves provides a soothing background as you catch up with mates.
Sounds lovely, right? It is. Until you realize that the fish you’re eating isn’t fish… it could be an endangered shark species. That puts a damper on the mood! Scientists have rung the alarm bell for sharks for years now, citing overfishing as the biggest threat these animals face – a study in 2021 declared that one-third of chondrichthyans (the sharks, rays, skates, and chimaeras) are threatened with extinction globally. And a new study just recently showed that nearly two-thirds of coral reef shark and ray species worldwide are threatened with extinction. So why is endangered shark meat being sold as ‘flake’ fillets in some fish and chip shops in South Australia, as new research has revealed.
The seafood industry is grappling with an increasing issue of food fraud, which includes a lack of confidence in the authenticity and provenance of seafood products coupled with complex and obscure supply chains. Sharks make up a small percentage of overall seafood trading. Across the globe, they are fished for their meat, fins (e.g. shark fin soup), liver oil, cartilage (for medicinal purposes), and skin (for leather). There are several shark species traded in Australia using the generic name ‘flake.’ However, this ambiguous nomenclature can also complicate regulatory agencies’ understanding of what species are being traded. As the authors of the new study point out, the use of the commercial label flake has been recommended by the Australian Fish Names Standards (AFNS) AS SSA 5300 to only include gummy shark (Mustelus antarcticus) and New Zealand rig (Mustelus lenticulatus), both of which have sustainable populations for fishing.
“However, the use of AFNS is not mandatory in Australia, and this creates the risk of multiple species of shark being sold under the umbrella label of flake,” they explain. “Ultimately, the lack of clear national guidelines or labelling laws that safeguard authenticity and compliance on the sale of shark meat (e.g., show species or origin of catch) potentially opens the door to fraudulent practices.” Since this dish plays an important role in Asustralian beach culture and traditional fish and chip sales, a team of researchers from the University of Adelaide analyzed the DNA of fish fillets from more than 100 retailers in Adelaide and regional South Australia to find out what kind of fish was being sold.
“Only 27 per cent of all samples were identified as gummy shark (Mustelus antarcticus), a species that has a sustainable population, and is one of only two species that is recommended to be labelled as flake in Australia,” first author Ashleigh Sharrad told 9 News. According to the study published in the journal Food Control, at least nine species were identified, including some species that are not found in Australian waters. A total of four species, including the CITES Appendix II listed short-fin mako (Isurus oxyrinchus) and smooth hammerhead (Sphyrna zygaena), were listed.
Only 11% of the samples and shops identified the species correctly, another 20% were mislabelled, and the remaining had only ambiguous labels. But are the shop owners to blame? “It is important to note that while a broad variety of species are being sold as flake, smaller retailers can’t be accused of mislabelling because they are most likely unaware when they purchase bulk, processed or frozen fish fillets,” Sharrad said. “Our results highlight the need for clearer national guidelines or labelling laws for shark fillets.”
Despite the frustration of scientists who work to protect these animals, the study shows DNA barcoding is an effective means of testing ambiguous labels on shark meat products. By doing so, policy, management, and compliance efforts can mitigate mislabelling, empowering consumers to make informed choices and promote sustainable fishing. In addition to threatening the conservation of species, food fraud also is potentially damaging human health and the economy. Seafood is one of the top food allergens and anaphylactic and systemic immunological reactions can result from accidental allergic exposure to seafood due to mislabeling of species. And according to a study conducted in 2020, illegal, unreported, and unregulated (IUU) fishing costs the global economy US$26-50 billion since it accounts for as much as 55% of product sold in some countries. Some companies and countries are turning to blockchain while others have adopted DNA tissue sampling and barcoding to make sure their products are what they’re supposed to be.
“This is the key to building trust across the supply chain, boosting demand for local, sustainable catch and importantly, empowering consumers and retailers to make informed choices,” Sharrad said. Want to make sure your seafood is sustainably caught? Consumers in Australia can download the GoodFish Australia app on their phones while those in the USA can use the Monterey Bay Aquarium’s Seafood Watch app.