Major UK supermarkets including Sainsbury's, Tesco, and Lidl are selling tinned products labeled as mackerel that do not contain the traditional oily fish, an investigation has found. These products often feature Chilean jack mackerel, a species from a different family of fish than true mackerel, which contains significantly less omega-3 fatty acids.
True mackerel, belonging to the Scombridae family, is highly regarded for its rich omega-3 content, essential for heart health, brain function, and preventing dementia. Chilean jack mackerel, from the Carangidae family, has about half the omega-3 content of true mackerel. Despite this nutritional difference, retailers continue to sell these products under signs that group both types of fish together.
Princes, a major tinned fish producer, switched its mackerel range to Chilean jack mackerel last year. This shift was largely driven by sustainability concerns, as North Atlantic mackerel fisheries have exceeded recommended catch limits for over 15 years and lost their Marine Stewardship Council certification. Chilean jack mackerel, however, is certified as sustainable.
Consumer Impact and Labeling
Sue Davies, head of food policy at Which?, expressed concern that consumers may be paying the same price for a product with diminished nutritional value. "It's a real concern when manufacturers quietly downgrade everyday staples like these as shoppers can end up paying the same price for a product that delivers significantly less nutritional value," Davies stated.
Some shoppers have noted changes in taste and texture, describing the fish as less oily and having a metallic smell. Canned seafood reviewer Marcus Ansell reported that the fish "smells rather metallic...like cheap rubbish tuna."
While Chilean jack mackerel is approximately 30% cheaper than true mackerel, the price discrepancy in stores is often minimal, with a difference of only about 20 pence. Until recently, UK regulations required Chilean jack mackerel to be explicitly labeled as such. However, shortly after Princes introduced its new tins, the Department for Environment, Food and Rural Affairs amended its rules, allowing the less specific 'jack mackerel' labeling. Critics argue this change blurs the distinction and potentially misleads consumers.
"Consumers will be suffering because pure mackerel is a much better species to eat than jack mackerel," said Stewart Harper, former managing director of North Atlantic Fishing Company.
Despite these changes by major brands, some supermarket own-brand tinned mackerel products continue to contain true mackerel.