Mackerel stocks are under severe pressure, with experts warning that the species is approaching a critical tipping point due to continued overfishing.

The Marine Conservation Society (MCS) has downgraded mackerel in its latest Good Fish Guide and is urging consumers to switch to more sustainable alternatives, such as herring.

The MCS publishes the Good Fish Guide annually to help consumers and businesses make informed seafood choices. North-east Atlantic mackerel, for example, once plentiful and viewed as a more sustainable fish choice, has, over the last four years, been overfished by an average of 23%.

Alice Moore, the manager of the Good Fish Guide at the MCS, said: “It’s deeply concerning to see a source of seafood that was once a sustainable choice in such decline. Mackerel is under immense pressure from fishing activities across multiple nations, and the stock will soon be no longer able to sustain itself. We are witnessing a steady decline in numbers, and they are nearing a breaking point. Immediate action must be taken by the UK government to work with other nations to align catch limits with scientific advice.”

The guide evaluates the sustainability of fish stocks using a traffic-light system, alongside a 1 to 5 rating scale. Green ratings (1 and 2) indicate the best choices, amber (3 and 4) signals the need for improvement, and red (5) designates fish to avoid. Businesses, including supermarkets and restaurants, are advised to source only species rated between 1 and 3.

North-east Atlantic mackerel, once considered a sustainable option, has now been downgraded due to consistent overfishing. Stocks caught using midwater trawl nets—commonly used by commercial suppliers—have been downgraded from a 3 to a 4, pushing them into the “avoid” category for businesses. Even mackerel caught using the more selective hook-and-line method has slipped from a 2 to a 3 rating.

The MCS says countries including the UK, Norway, Iceland, and the Faroe Islands have routinely exceeded scientifically advised total allowable catches (TACs). Since 2009, these catch limits have surpassed recommended levels by 5% to 80%. Between 2020 and 2024, the average overage was 39%.

Instead of mackerel, the MCS encourages consumers to try more sustainable species such as herring from the North Sea and eastern Channel, or Cornish sardines. The guide also includes some positive updates: monkfish from the North Sea has improved from amber to green, and blue marlin has been removed from the red list.

What Seafood Should You Choose Instead?

• Mussels: UK-farmed mussels are described as “seafood superheroes.” They’re cultivated in environmentally friendly ways and harvested by hand, making them an excellent sustainable choice.

• Avoid the Big Five: Cod, haddock, salmon, tuna, and prawns dominate UK seafood consumption, but lesser-known alternatives like coley and hake are often more abundant and eco-friendly.

• Shop Locally: Visiting a local fishmonger allows consumers to get advice on what’s fresh, in season, and sustainable. They can also offer more affordable, locally caught fish options.

• Tinned Options: Tinned sardines from Cornwall and anchovies from the Bay of Biscay are good shelf-stable choices with low environmental impact.

• Whole Fish: Choosing whole fish such as hake, plaice, or lemon sole—especially from the North Sea—can be more economical and reduces waste. Every part can be used, even for making homemade fish stock.

By choosing wisely, consumers can help protect dwindling fish stocks and support more sustainable seafood practices.

 

 

——————————————————————————

At Natural World Fund, we are passionate about restoring habitats in the UK to halt the decline in our wildlife.

 

Donate now and join in the solution!