Think You're Buying Mackerel? UK Suppliers Swap It for Cheaper Fish With Half the Omega-3

Mackerel, long one of Britain's cheapest sources of omega-3, is being withdrawn from supermarket shelves and replaced with other fish. Some of the substitutes carry far less of the nutrient that made the oily fish a low-cost health staple.

Waitrose became the first UK supermarket to suspend sourcing of North East Atlantic mackerel, announcing the move on 26 February 2026 and clearing fresh, chilled, and frozen stock by 29 April. Tinned mackerel is following once existing supplies sell through.

In its place Waitrose has introduced a new range that includes Marine Stewardship Council (MSC) certified hot smoked herring and frozen sardine fillets, an Aquaculture Stewardship Council (ASC) certified hot smoked sea bass, and an RSPCA Assured hot smoked trout with dill and lemon.

The Omega-3 Gap Between Mackerel and Its Substitutes

The substitutes vary widely in omega-3 content. Atlantic mackerel provides roughly 2.6 grams per 100 grams, among the highest of any fish. Sardines offer around 1.4 to 1.5 grams, close to half that figure, while herring sits near 1.7 grams. Sea bass, a leaner fish, holds only a fraction of what oily mackerel delivers.

The NHS advises at least one portion of oily fish a week, and mackerel has long been a low-cost way to meet it.

Why Mackerel Is Vanishing From UK Shelves

The reason for the disappearance lies in the state of the stock. The MSC suspended North East Atlantic mackerel from its certification programme in March 2019 because of overfishing and the failure of fishing nations to agree how to divide the catch.

In September 2025 the International Council for the Exploration of the Sea (ICES) recommended cutting catches by about 70 per cent to let the stock recover.

Coastal states fell well short of that. In December 2025 four of them—the UK, Norway, the Faroe Islands, and Iceland—agreed a 2026 total allowable catch of 299,010 metric tonnes, a 48 per cent reduction on the previous year but far above the scientific advice. The European Union was left out of the arrangement again.

British shoppers are not the only ones affected. In the Netherlands, supermarkets including Jumbo, Lidl, and Albert Heijn had already dropped North East Atlantic mackerel before Waitrose acted, after the consumer guide Viswijzer red-listed the fish. Albert Heijn brought in smoked Atka mackerel from the North Pacific and the Bering Sea, a different and more expensive species.

Fishers Push Back Against the Ban

Not everyone in the industry accepts the decision. Those retailer moves followed downgrades of mackerel by ratings bodies, among them the Marine Conservation Society (MCS).

Ian Gatt, chair of the Scottish Pelagic Sustainability Group, criticised the MCS rating, telling trade publication SeafoodSource that it 'fails to reflect recent management and scientific developments that will deliver a significant reduction in fishing pressure.' The group said the MCS should have kept the rating under review until the next scientific assessment, expected in September 2026.

Adam Wing, of the industry body Seafood Scotland, said British fishers had stayed within advisory limits and were being penalised for the failings of others. 'Consumers can quickly lose confidence in a product through a negative campaign, but mackerel is a healthy and affordable protein and needs to be accessible on the shelves,' he said.

He added that canned mackerel features in the Seafood in Schools project as an introduction to eating seafood.

The WWF urged all UK retailers in November 2025 to stop sourcing mackerel with immediate effect.

No Timeline for Mackerel's Return

Waitrose has described the suspension as temporary. 'Our customers trust us to source responsibly, and we are closely monitoring the fishery. We look forward to bringing mackerel back to our shelves once it meets our high sourcing standards,' said Jake Pickering, the retailer's head of agriculture, aquaculture, and fisheries.

There is no date for that return. The MSC keeps the fishery suspended until every nation fishing it, including the EU, agrees on quota shares in line with science, and it currently points shoppers towards jack mackerel, a different family of fish, as a certified alternative.

For now, mackerel remains hard to find on UK shelves, and the fish replacing it can carry less omega-3.