Fish and Seafood fraud: Species mislabelling

Fish fraud is a major global issue. The FoodChain ID Fraud database currently lists hundreds of incidents of fish and seafood fraud that have occurred over the last four decades; however, the true extent of fraud in the fish and seafood industry is unknown, as most incidents are unreported.

Species mislabelling is one of the most common type of fraud

One in five seafood samples is mislabelled, according to a 2016 review by Oceana of more than 200 studies from 55 countries. In a local study, 31% of fish samples collected from South African retailers were found to be different species to the ones indicated at the point of sale.

Poor traceability drives mislabelling

Global fish supply chains tend to be complex, and trading practices in the fishery sector are generally poorly monitored. This makes traceability difficult and creates opportunity for products to be labelled incorrectly.

Fish and seafood species may be mislabelled unintentionally, due to accidental species misidentification or a loss of product information along the supply chain.

However, mislabelling may also be deliberate, motivated by economic gain (e.g. replacing a high-value species with a lower-value ‘imitation’ species) or ethical limitations (e.g. replacing a sustainable species with a species that is considered at risk).

Mislabelling poses food safety concerns

Whether intentional or unintentional, mislabelling is misleading to consumers and is a violation of the Consumer Protection Act (68 of 2008).

Besides authenticity discrepancies and ethical concerns, mislabelling may also pose several health risks. For example, a marine fish species may be replaced with a farmed species from a polluted watercourse; or a non-toxic fish species could be replaced with a toxic substitute species. A good example of this is the mislabelling of pufferfish as another fish species.

Most pufferfish species are highly toxic, with the internal organs containing high concentrations of a potent neurotoxin known as tetrodotoxin. In Japan, Korea and China, some pufferfish species are considered a delicacy; however, they must be prepared by specially trained chefs who know which parts are safe to eat and in what quantity. Improperly prepared pufferfish can be lethal.

In 2007 and 2019, puffer fish from China was mislabelled as monkfish and sold in the United States of America. This act of food fraud, whether accidental or deliberate, posed serious health risks to consumers.

Another concern with fish species mislabelling is the potential risk to allergic consumers. Although most people with a fish allergy are allergic to a range of species, some individuals may be allergic to only one species of fish (mono-allergy). Thus, if a fish species is labelled incorrectly and consumed by one of these individuals, thinking the fish product is something that it is not, their health may be in jeopardy.

Labels only provide some guidance

Seafood labels in the EU are required to state both the scientific and the common name of the fish product, as well as the catch area, fishing gear category, and an identification mark. This level of detail is not required in South African legislation.

In South Africa, the Regulations relating to the labelling and advertising of foodstuffs (R. 146) do not provide any label requirements for unprocessed fish that has not been prepacked; and indicates that prepacked* unprocessed fish should be labelled with the type of fish (but does not give any further detail).

*The identity of the contents of the package should be clearly visible.

Along with WWF and other partners, SABS has developed a voluntary food labelling standard (Approved market names for South African fish and related seafood species, SANS 1647) that requires the species name, origin and the fishing method to be indicated on the label of fish and seafood products.

WWF-SASSI encourages the use of this labelling standard; however, given that SANS 1647 is not legislated and is voluntary, many retailers and suppliers do not use it.

The absence of mandatory detailed labelling requirements may increase the risk of mislabelling – particularly of fresh fish products.

Testing for mislabelling

The species of a fish or seafood sample can be confirmed or identified through testing.

When testing for food fraud and authenticity, DNA and proteins are useful target analytes. This is because they contain unique information: DNA is made up of unique sequences of nucleotides and proteins consist of unique chains of amino acids. The DNA or protein of a sample can be extracted, analysed, and matched to a reference library of predetermined sequences to establish to which species the sample belongs.

DNA-based techniques

For single species products, DNA sequencing (or DNA barcoding) techniques are able to identify the species of a sample.

For products containing two or more species, DNA sequencing is not suitable. Instead, a next generation sequencing (NGS) technique known as meta-barcoding can be used.

DNA-based techniques have some limitations for food samples. In processed food products, DNA may be degraded as a consequence of food production processes. Changes in temperature and pH can cause DNA to unwind and fragment, which may render the DNA undetectable by the test method. This can lead to unsuccessful analyses or false negative results.

Protein-based techniques

Because DNA may be degraded during food production processes, protein-based techniques may be more suitable for determining the authenticity of fish species.

Proteins are more stable to food production processes compared to DNA. Although proteins may denature and fragment into peptides (short amino acid sequences) when exposed to temperature and pH changes, they are unlikely to break down further into their constituent single amino acids. Peptides are generally conserved during food production, making them useful target analytes.

Testing plays an integral role in the food fraud journey. It is a valuable tool that helps confirm product authenticity, which in turn, protects brand integrity.

Because there are many factors to consider when testing for mislabelling, it is best to discuss your request with the testing laboratory to ensure that the method used is appropriate and reliable. For more information, please contact FACTS.

Other articles you may be interested in:
FISH AND SEAFOOD FRAUD: Concerns beyond mislabelling
CASE STUDY: The murky waters of the tuna controversy