UK supermarkets are increasingly turning to Chilean jack mackerel for some tinned fish ranges as falling Atlantic mackerel stocks put pressure on supplies and sustainability credentials.

Retailers including Tesco and Sainsbury’s have begun stocking canned products made with jack mackerel, a different species to Atlantic mackerel, as the grocery sector responds to concerns around overfishing and dwindling stocks.

Years of disagreement have taken place between countries fishing North-East Atlantic mackerel over how catches should be divided.

Combined quotas have repeatedly exceeded scientific recommendations, with the Marine Stewardship Council warning that mackerel stock biomass has now dropped below a critical threshold. Scientists recommended a 77 per cent reduction in catches for 2026 to give stocks a greater chance of recovering.

North-East Atlantic mackerel fisheries have been without MSC certification since it was suspended in 2019 amid concerns over the management of stocks.

The pressure has encouraged suppliers and retailers to look further afield, including to Chilean jack mackerel, which remains available from MSC-certified fisheries.

Princes launched a range of 100 per cent MSC-certified jack mackerel into the UK market earlier this year as part of its 2026 product development programme.

Its jack mackerel lines, which include fillets in tomato sauce, sunflower oil and extra virgin olive oil, are now stocked by major grocers including Tesco and Sainsbury’s.

A 125g tin of Princes jack mackerel in extra virgin olive oil is currently listed at Sainsbury’s as originating from Chile, while Tesco lists several Princes jack mackerel products within its tinned mackerel category.

However, jack mackerel is not the same fish as traditional Atlantic mackerel.

Despite its name, jack mackerel belongs to the Trachurus group, while Atlantic mackerel is part of the Scomber genus. UK commercial fish designations allow species of Trachurus to be marketed as “jack mackerel”.

The substitution has prompted questions around whether shoppers clearly understand the distinction between the species, particularly given that products can sit alongside conventional mackerel in supermarket aisles.

The Financial Times reported that some consumers and seafood experts have also raised concerns over differences in flavour, texture and nutritional profile.

Princes describes its jack mackerel as having a “milder flavour and meatier texture”, with its tomato sauce variety containing 0.7g of omega-3 per 100g and its sunflower oil version containing 0.9g.

The switch comes as rising sea temperatures have also complicated management of Atlantic mackerel stocks.

The MSC said the species has shifted northwards since 2007 as waters have warmed, creating further disputes between countries over access to fishing grounds and how quotas should be allocated.

Its collapse in certification has become a growing headache for supermarkets and seafood suppliers trying to meet sustainable sourcing commitments while maintaining affordable tinned fish ranges.

Processors across Europe have consequently been diversifying into alternatives including Chilean jack mackerel and chub mackerel as Atlantic supply tightens and prices rise.

The shift highlights the growing impact that climate change, international quota disputes and sustainability requirements are having on the products appearing on supermarket shelves.

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