Consumer watchdog warns surge in cheap ‘jack mackerel’ may signal ‘skimpflation’ across UK supermarkets

The consumer champion Which? cautions that the expanding presence of jack mackerel tins—a budget‑friendly, nutritionally weaker cousin of the classic Atlantic mackerel—could be a fresh example of \"skimpflation\". The phrase, introduced by the organisation, refers to a quiet decline in product quality or amount while prices stay steady, leaving buyers with reduced value for the same spend.

Skimpflation is distinct from outright price inflation because the tag‑along price stays largely unchanged, yet the product’s substance is subtly trimmed. Amid ongoing cost‑of‑living strains, retailers feel mounting pressure to keep shelves filled without shifting higher raw‑material expenses onto shoppers. Swapping in a cheaper fish species offers one route to that equilibrium, but it also raises concerns about hidden public‑health costs.

Jack mackerel (Trachurus spp.) is a smaller, faster‑growing fish that fetches a lower market price than the richer, oil‑laden Atlantic mackerel (Scomber scombrus). Although both belong to the same family, the former provides markedly less omega‑3 fatty acids and overall protein, making it a less nutritious choice for consumers who depend on canned fish as an inexpensive source of essential nutrients.

Supermarket chains, squeezed by tighter margins and erratic fish supplies, have broadened their canned jack mackerel range, often branding it under generic \"mackerel\" labels. Analysts link the move to climbing wholesale prices for Atlantic mackerel, stricter fishing quotas, and the fallout from Brexit‑related trade disruptions on import volumes. The outcome is a more visible cheaper alternative lining everyday grocery aisles.

For shoppers, spotting the swap can be tricky, especially when packaging fails to clearly label the species. Which? notes that many buyers might assume they are purchasing the same health‑benefiting fish they have bought for years, potentially undermining dietary goals without their knowledge. The group urges consumers to scrutinise the fine print, searching for scientific names or explicit species listings, and to compare the nutritional facts on the tin’s back.

Industry bodies and food‑safety regulators have not yet issued a formal comment, but Which? says the episode highlights the need for tougher labelling standards. Should the practice become widespread, it could push the Food Standards Agency to revisit guidelines on species disclosure for canned fish products. Meanwhile, the consumer group advises shoppers to stay alert and consider alternative protein sources if nutrition is a priority.