Sushi bars and shops are regularly mis-selling exotic species of fish to unwitting British consumers.
In cases cited in a new study published by Salford University, many fish were sold under a generic name that revealed little about where they came from. Some of the species were endangered, while others were so rare that little was known about their population size, the researchers noted.
The findings suggest that an increasingly complex and globalised food supply chain is open to abuse, putting exotic species at risk.
“This is about transparency,” said Professor Stefano Mariani, a conservation geneticist at Salford University. “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,” he explained.
Professor Mariani and his colleague Cristina di Muri tested samples from grocery shops in Liverpool and Manchester. They found fish labelled as red snapper – a tropical fish used in Caribbean cooking – was actually redfish, a cold water Atlantic species. Some products labelled mackerel turned out to be either Indian mackerel, which is found in the Red Sea and Polynesia, or hilsa shad, a type of tropical herring mostly found around the Indian and Arabian peninsulas.
When asked about the types of fish they were selling, most of the shops “had no detailed knowledge and just said they were selling ‘fish’”, Professor Mariani said.
Mariani and di Muri suggested that most of the samples identified in their study were unfamiliar to British diners because they had appeared only recently in the UK market, largely because of the growing number of shops catering to different ethnic groups.