Sustainably caught North Sea cod could disappear from UK supermarket shelves next year after it was announced that certification is being suspended following a dramatic decline in populations.

Cod populations in the sea had been thought to be in good health but the latest scientific advice has revealed much lower amounts of fish, putting the fishery at increased risk of collapse.

The decision by the Marine Stewardship Council (MSC) means North Sea cod is coming off the menu again for consumers who want their fish supper to be sustainable, just two years after the fishery secured the “blue tick” eco-label.

MSC certification, which allows seafood and fish products to carry the label that shows it comes from sustainable fisheries, will be suspended from all MSC-certified fisheries targeting North Sea cod from 24 October.

The news deals a blow to the fishing industry, which has introduced measures to avoid catching young fish, such as closing large spawning areas to fishing, trialling new nets, and avoiding areas where cod congregate to avoid catching them when fishing for other species.

The North Sea cod fishery supplies a relatively small amount of the 115,000 tonnes of cod eaten every year in the UK. Most (94%) – including the vast majority of that sold in the UK’s chip shops – is imported from Iceland or the far larger Barents Sea population, caught by Norway and sometimes Russia. The Icelandic and Norwegian cod are both MSC-certified.

The loss of certification will mean that it will be harder to sell the cod to UK supermarkets, although that will also depend on what quotas are eventually agreed for the fishery.

Erin Priddle, the UK and Ireland programme director for the MSC, said: “The decline in the North Sea cod stock is a worrying development, with the latest stock models suggesting that the fishery has not recovered as well as previously thought.”

The latest scientific advice from the International Council for the Exploration of the Sea (ICES) meant the North Sea cod fishery no longer met the MSC standard, she said. “While this news is devastating for industry, it is a testament to the MSC standard working as it should: to pick up on threats to stock sustainability, as is the case with North Sea cod.”

The fishery won its sustainability certification in 2017, when populations were assessed as reaching 152,207 tonnes – the highest since 1982 and a decade since they came close to collapse.

Populations were forecast to hit 180,990 tonnes in 2018, but the scientific advice for that year included a far smaller estimate of the amount of cod in the North Sea. This year’s advice from the ICES revealed estimates of only 81,224 tonnes, below the “safe biological level” for the population and putting it at increased danger of collapse.

Chris Thorne, oceans campaigner at Greenpeace UK, said: “The MSC withdrawing North Sea cod’s sustainability certificate reflects what we already knew: our cod, like our oceans, are in crisis. Industrial over-fishing has driven stocks of cod in the North Sea to the point of collapse again, but despite this governments continue to ignore the science and allow overfishing to continue.”

Aoife Martin, the director of operations at Seafish, the organiser of the annual national fish and chip awards, said: “North Sea cod is still a sustainably managed fishery and fishermen can still catch it within the agreed limits, there will just be less of it available to buy. The decision to reduce the allowed catch is a great example of responsible fisheries management.”

Sustainable cod’s off the menu. What to eat instead:

Try to buy fish with MSC labels. Sustainable choices include:

• Cod from Iceland or Norway.

• Haddock.

• Hake.

• Pollock.

• Pacific cod.