North Sea cod, a staple for the UK's fishing industry, has lost its sustainable status, after stocks were found to have almost halved in the last two years.
Cod caught around the UK received the "blue tick" sustainability label in 2017, when stocks of the fish were put at around 152,207 tonnes – its highest level since 1982.
However, new advice from the International Council for the Exploration of the Sea (ICES) puts the stocks at only 81,224 tonnes – more than 100 tonnes less than predicted.
The current level of cod stocks in the North Sea is now below the "safe biological level", according to ICES, with the species in danger of being wiped out from the area.
The blue tick mark indicates that fish has been caught from sustainable fisheries – but North Sea cod caught after 24 October will not bear the certification.
Experts are not certain what has fuelled the fall in fish stocks, but some suggest that climate change could be making the waters warmer and driving the cod away, and that fewer younger cod are surviving into adulthood.
The British fishing industry has recently put plans in place to consciously avoid catching the younger fish by using new nets and closing off large breeding areas to fishermen – initiatives that helped fisheries gain its sustainability status in 2017.
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People in the UK eat around 115,000 tonnes of the fish a year, but it is now mostly imported from outside the North Sea from places like Russia, Norway and Iceland, according to the Marine Stewardship Council (MSC).
Reacting to the move to strip the caught fish of the blue tick, 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.
"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.