Researchers Say You Have No Idea What’s In Your Sushi

The fish in the supermarket sushi selection box you grabbed for lunch today might not match up to the delicate norimaki crafted by a qualified sushi chef, but at the very least, you'd expect the mackerel in its saba nigiri to actually be mackerel. And hope that, even if the species isn't specified, the tuna in your maki is sustainable. But according to a report from researchers at the University of Salford, this could all be wishful thinking. The fish in much of the UK's shop-bought sushi is actually mislabelled.

Published last March in the PeerJ journal, the research found that 10 percent of the 115 samples of fish taken from 31 sushi restaurants across England over a 12 month period were labelled incorrectly and inadequately, containing different fish varieties to those listed on the packaging. Fish labelled as red snapper, for example, was actually redfish, and endangered species were being sold under generic terms like "tuna" and "eel."

The results from the paper were presented by the Salford researchers at the Symposium of the Fisheries Society of the British Isles earlier this month. They warned that food fraud could be occurring at any stage of the fish supply chain, from the fishing boats and processing plants through to the retail counter, and called for more transparency for consumers.

Speaking at the symposium, Professor Stefano Mariani, conservation geneticist at the University of Salford and co-author of the study, said: "People don't know what they are buying. There is now a huge trade in lesser-known species that have not been assessed. We are talking about hundreds of species of fish. We found they are just not being correctly labelled. Imagine how impossible it is for a consumer to make an informed purchasing decision."

MUNCHIES reached out to Mariani to find out more about the consequences of sushi shops selling mislabelled fish. He told us: "There are so many ripple effects that can come from this issue. It can have consequences for people's health. You have so many types of seafood, some of which can be toxic, nausea-inducing, allergy-inducing. If you get served something that is potentially harmful to your digestive system, it can be dangerous."

Mariani continued: "There's also the environmental aspect, which means that you end up flooding the market with products which are endangered in the sense that they are at the point of depletion of their stocks. If we just use umbrella terms like 'tuna' or 'snapper,' we're preventing the consumer from having any idea of whether they are purchasing a species which is sustainably caught. These names refer to dozens of different species."

This is by no means the first time that researchers have uncovered fishy goings-on in the seafood industry. Last year, marine conservation group Oceana found that in 25,000 samples of seafood, one in five were mislabelled and that in many cases, the substituted fish was endangered.

But according to Seafish, an organisation that offers regulatory guidance to the UK seafood industry, things are getting better. Regulatory affairs advisor Hannah Thompson told us: "It is important to remember that regulation in the European and UK food industry is continually evolving in line with industry practice. Since the data was collected for [the Salford University] study, some of these regulations such as requirements for traceable seafood from catch or harvest to the retail level, including restaurants, have been strengthened."

Thompson continued: "Consumers should be encouraged to ask questions about the seafood they are eating out of the home. If they have doubts they should contact their local trading standards in the first instance. They can also contact Food Crime Confidential, a reporting facility run by the Food Standards Agency where anyone with suspicions about food crime can report these safely and in confidence, over-the-phone or online."

But what are the high street sushi chains doing to ensure best sourcing and labelling practices? A spokesperson for itsu told MUNCHIES: "We work closely with suppliers to ensure the highest welfare standards are maintained, every single fish is traced from harvest to fork. We use allocated lot numbers which trace every fish, right back to the harvest. This robust tracing procedure ensures customers receive 100-percent label accuracy. Our ingredients are listed, you'll see we use line caught yellowfin tuna."

YO! Sushi had not responded at the time of publishing.

Professor Mariani suggests that as well as a more tightly controlled fish supply chain, education is key. He said: "It's important that the supply chain is better controlled and countries agree on a tight and standardised system, so if fish is caught, processed, and sold in different countries, the fish trail can be tracked. But I do believe that if we want to help ourselves, then we need to teach people to better recognise different types of fish and be more aware about how food comes to our table."

Bottom line, if you really want to make sure the sushi you eat al desko is the real deal, best to make it yourself.