Research: Mislabelled shark meat found in Australian markets

Research by Macquarie University has revealed widespread mislabelling of shark meat in Australian markets, including the sale of threatened species, which the researchers say highlights a need for improved enforcement to protect consumers and shark populations.

Research found a significant portion of shark meat sold in Australian fish markets and takeaway shops is mislabelled, including several samples from threatened species.

The study, carried out by Masters of Research candidate Teagan Parker Kielniacz, supervised by Nicolette Armansin and Professor Adam Stow, collected 91 samples of shark meat from 28 retailers across six Australian states and territories.

Using DNA barcoding, a technique that matches genetic sequences to a reference database, they identified the species of each sample and compared it to the label applied by the retailer.

Around 70% of the samples were mislabelled, either because the species did not match the label or the label did not comply with the Australian Fish Names Standard (AFNS).

Mislabelling was particularly high for samples labelled as “flake”, which the AFNS restricts to fish from just two sustainably caught shark species: the gummy shark and New Zealand rig shark.

The research found that 88% of flake samples were not from either of these species.

“Consumers assume that because you can buy flake, it is a sustainable choice, but it’s a bit more nuanced than that; most flake was not from sustainably caught shark species,” Parker Kielniacz said.

The study identified that nine of the samples came from three species listed as threatened in Australia, including the critically endangered scalloped hammerhead and school shark. All were sold as flake.

Mislabelling was markedly higher in takeaway shops compared to fish markets and wholesalers, indicating the problem worsens down the supply chain.

Setting a baseline

The research underscores the urgent need for improved labelling standards and enforcement, said co-author and research supervisor, Nicolette Armansin.

“Many shark populations are facing unprecedented declines worldwide, and yet consumers have little idea of the provenance of the fish they are eating, and they are not told they are eating a threatened species,” Armansin said.

While Australia is signatory to several relevant international conventions, including the 1982 United Nations Convention on the Law of the Sea (UNCLOS) and the 1995 United Nations Fish Stocks Agreement (UNFSA) on sustainable fisheries, the use of AFNS standards is only a recommendation.

“As long as Australia allows shark meat to be sold just as ‘shark meat’, we can’t enforce labelling standards, which is a problem for both consumers and for threatened species protection,” Armansin said.

“Without having a baseline that says this is what you need to tell consumers, there’s nothing to say you’re doing it poorly.

“Until labelling laws are taken more seriously for seafood in general, we’re chasing our tails because there’s no standard.”

Mass DNA testing

Adam Stow heads the conservation genetics laboratory at Macquarie University, where this research was conducted, and is corresponding author on the study. He said DNA testing is rapidly becoming cheap, flexible and fast enough to enable large-scale monitoring of the seafood supply chain.

“DNA barcoding is becoming quite an efficient and tractable way to monitor species of origin when it comes to fish, and in particular, sharks,” Stow said.

Rapid screening methods, such as testing bilge water from fishing boats or wastewater from fish markets, could be used to determine what species have been caught or traded.

“It’s possible to collect a sample from drains next to the fish stalls to identify exactly what species are being sold in that fish market and flag any species that is endangered.

“One way forward is to industrialise cheap and efficient means of large-scale DNA monitoring.”

The full research findings have been published in the journal Marine and Freshwater Research.

Image credit: iStock.com/Griffin24