Britons are being advised to think twice before buying UK-caught cod after the Marine Conservation Society pushed the species to the bottom of its sustainability rankings.

The charity said the fish has now fallen to a level where it can no longer be treated as a sustainable choice, reflecting what it described as severely weakened stocks.

The warning comes amid a wider decline in several familiar seafood staples. The Marine Conservation Society said overfishing remains the main driver of cod’s collapse, while warmer seas have added pressure by disrupting breeding and reducing the survival of young fish.

The Guardian reported that the charity is now recommending European hake as a closer substitute for shoppers who still want a white fish option.

Scientific concern over cod has been building for some time. The International Council for the Exploration of the Sea has advised a zero-catch approach for northern shelf cod in 2026, saying continued fishing could push parts of the stock below safe limits.

SeafoodSource reported that the proposal has drawn criticism from fishing interests, who warn of economic pain for coastal communities.

The pressure has also reached the negotiating table. According to the Council of the EU, ministers approved a 2026 fishing deal covering shared stocks between the UK and the bloc, with new quotas taking effect from 1 January.

In that context, the UK Government’s earlier decision to cut cod quotas by 44 per cent for 2026 reflected mounting concern over the state of the stock.

Cod is not the only species to lose favour with campaigners. The Marine Conservation Society has also downgraded trawled scampi and mackerel, while saying that pot- or creel-caught scampi remains a better option.

It continues to point consumers towards lower-impact British alternatives such as haddock, plaice, seabass, blue mussels and trout, as well as urging ministers to back fishing methods that give depleted stocks a chance to recover.

Sign up here to get the latest grocery and food news each morning