From Ocean to Plate

How DNA testing helps to ensure traceable, sustainable seafood

Seafood fraud – the selling of seafood products with a misleading label, description or promise – has become a widespread form of food fraud.

In fact a recent global analysis suggested that on average 30% of seafood products are misdescribed or mislabelled.

Although it is possible for seafood to become unintentionally mixed at various points in the supply chain, mislabelling threatens the bottom line of honest fishers and seafood traders, it also undermines the progress being made by sustainable fisheries and can allow illegal and unregulated fishing practices to go undetected.

A traceable supply chain is vital to delivering the MSC’s vision of healthy oceans and its promise to consumers that MSC labelled seafood comes from a sustainable source.

What is traceability?

In 2013, the ‘horsemeat scandal’ sent tremors through the European food industry.

The fraudulent replacement of beef with cheaper equine alternatives in burgers and convenience food left consumers and retailers reeling, alarmed that they had fallen victim to the largest food fraud in decades.

The scandal not only highlighted the shortcuts being made by food manufacturers in their attempts to compete for the lowest price, it emphasized the complexity of global food supply chains and the challenges in monitoring every step.

Almost overnight, the importance of traceability – the ability to track any food through all stages of production, processing and distribution – became high on public and political agendas.

Mislabelling motivations

It can be near impossible to accurately identify the species of fish present in a product from sight alone, as shown by these two battered fillets of Atlantic cod (left) and Pangasius (right).

Although it is possible for seafood to become unintentionally mixed with different species at various points along the supply chain, intentional seafood fraud is motivated by profit.

Scientific investigations have repeatedly revealed higher rates of mislabelling among premium, sought after fish like Atlantic bluefin tuna and wild-caught chinook salmon and lower rates in convenience seafood like fish fingers and processed seafood sticks.

Higher rates of mislabelling have also more commonly been reported in restaurants and take-away outlets than in food retailers.

The consequences
of mislabelled seafood

Whatever the incentive, the implications of seafood mislabelling can be alarming and wide ranging.

Illegal, unreported and unregulated (IUU)

IUU fishing refers to fishing activities that do not comply with national, regional, or international fisheries conservation or management legislation or measures.
Illegal harvesting affect the reliability of fisheries management models and can lead to inaccurate targets being set for legally caught fish. This can potentially contribute to the collapse of some stocks or hinder the recovery of others.

Consumer deception
Where fish are incorrectly labelled, these consumers could unwittingly be eating options that are less sustainable, or that do not meet their ethical criteria.

The trade of vulnerable and endangered species
A major obstacle to the traceability of seafood in some parts of the world is the inadequate naming and labelling of seafood as it travels along the supply chain.

In the USA, ambiguous names such as ‘grouper’ can legally be used to describe any one of 65 species of grouper, including the critically endangered Warsaw grouper.

Traceability Standard

Despite the clear threats posed by seafood fraud, there is hope. In 1999, the MSC developed its Chain of Custody Standard to ensure that every distributor, processor, and retailer trading in MSC certified sustainable seafood has effective traceability systems in place.

It assures consumers that the MSC labelled seafood they buy has been sourced legally from a sustainably managed source, has not been mixed with uncertified seafood, and can be traced along the supply chain from ocean to plate.

Today, over 3,000 companies worldwide are MSC certified. In order to sell MSC labelled seafood, each company along the supply chain must have a valid MSC Chain of Custody certificate and pass regular independent audits to retain it.

DNA testing

The colour, shape and texture of fish and other marine species can often be altered beyond recognition during the manufacture of seafood products.

This makes it near impossible to accurately identify the species of fish present in a product from sight alone. But regardless of how a seafood product is stored (fresh, canned, frozen), and what form it is in (fillet, eggs, fin, processed product), even the smallest fragment will contain a unique genetic code.

By comparing a particular segment of DNA with a reference library holding the genetic codes of most fish species, scientists can identify exactly which species is present in a sample and, for some species with very distinct populations, where in the world that species was caught.

Since 2009, the MSC has commissioned DNA tests on hundreds of MSC certified products, from all over the world. In combination with product tracebacks and supply chain volume reconciliations, the MSC’s DNA testing program is used to monitor the effectiveness of the MSC Chain of Custody certification program, and to verify the authenticity of products carrying the blue MSC label.

The MSC’s latest
DNA testing results

The latest tests have revealed that 99.6% of MSC labelled seafood is correctly labelled.

The study sampled 256 unique products and 13 species of fish, sourced from retailers across 16 countries.

Given the high levels of mislabelling found in the open market, the results of the MSC’s DNA testing program are very positive. For example, a recent scientific meta-analysis comparing 51 similar DNA surveys for a total of 4,500 samples of seafood (primarily sampled from the retail sector) revealed an average global mislabelling rate of 30%.

Nevertheless, any anomalies are thoroughly investigated and corrections made to ensure that the MSC Chain of Custody Standard continues to be applied correctly.

MSC 2015 DNA test results by geography and number of MSC labelled product successfully tested

In the most recent round of MSC’s DNA testing program, the one mislabelled product identified was a frozen fish fillet from a European retailer, labelled as MSC certified Southern rock sole.

The DNA test results instead identified the product as Northern rock sole.

This single incident was investigated by tracing back the documentation through the supply chain, notifying the related certification bodies, and informing the brand owners of the result.

It was concluded that the results do not show any evidence of deliberate substitution of an MSC certified species with a non-certified species, but rather the accidental mix-up of two closely related species caught in MSC certified fisheries.

Conclusions and
future plans

The results of the MSC’s DNA testing program are very positive. They assure consumers that the MSC seafood that they buy has been sourced from a sustainably managed source, has not been mixed with non certified seafood, and can be traced along the supply chain from ocean to plate.

Nevertheless, the MSC takes traceability very seriously and continues to monitor the certified seafood supply chain very closely.

Looking to the future, the scope of the MSC’s testing program will be broadened to include more seafood products and will explore the use of new technologies to verify the authenticity of products that are more difficult to test using DNA.

Share this story:

Read the full report
More MSC stories
The MSC on Facebook

Dr Lucy Anderson,
Science Communications Manager,
Marine Stewardship Council

All images subject to copyright
Nice and Serious
Paul Winch-Furness
Felipe Caparrós Cruz
Ulf Berglund