Supermarkets are increasingly offering jack mackerel as a substitute for the traditional Atlantic variety, a move consumer groups are labeling "skimpflation" due to the fish's lower nutritional value and cost. This shift comes as Atlantic mackerel populations have seen a dramatic decline.
Jack mackerel, while similar in name, is a different species belonging to the Carangidae family, distinct from the Scombridae family of traditional mackerel. Until December 2025, UK law restricted the marketing of Carangidae species to terms such as "jack," "scad," "trevally," or "horse mackerel." However, regulatory changes following the launch of "jack mackerel" products now permit this labeling.
Industry analysis suggests that Chilean jack mackerel, commonly used in these products, costs approximately one-third of the price of Atlantic mackerel. This economic incentive is amplified by the ongoing "mackerel war," a protracted dispute over fishing quotas involving the UK, Iceland, Greenland, Norway, the Faroe Islands, the EU, and Russia. These nations have struggled to reach agreements on sustainable catch limits aligned with scientific recommendations.
Over the past 15 years, mackerel catches in the north-east Atlantic have, on average, exceeded scientific advice by 39%. Data from the International Council for the Exploration of the Sea (Ices) indicates that stocks have diminished by roughly 75% over the last decade. Ices has recommended a nearly 70% reduction in north-east Atlantic mackerel catches for 2026 to facilitate stock recovery.
Last year, the Marine Conservation Society declared the Atlantic mackerel population to be at "breaking point." Consequently, the fish has lost its Marine Stewardship Council (MSC) certification, a standard that many retailers adhere to for sustainability. Chilean jack mackerel, however, retains its MSC certification.
Retailers have begun to react to these concerns. In February, Waitrose announced it would halt sales of fresh, chilled, and frozen mackerel, with tinned products to be phased out. This decision was lauded by the Marine Conservation Society as "leading and decisive." The move toward jack mackerel is not confined to the UK; supermarkets in the Netherlands have stopped selling Atlantic mackerel, and at least one Swedish supermarket has also switched to jack mackerel.