North Sea cod stocks are on the road to sustainability, according to Marine Stewardship Council (MSC) research.
The council, which certifies whether fish are being caught sustainably, says it is too soon to tell exactly when the North Sea fishery will be sustainable.
But a spokesman said on current trends, it will be ready for certification within years rather than decades.
Stocks would still be in recovery then, James Simpson said, but they would have passed an acceptable level.
MSC certification is determined by the state of the stocks, the environmental impact of the fishery, and if there is a management system in place to maintain sustainability if circumstances change.
The latter two were already in place, Mr Simpson said.Continue reading the main story
End Quote James Simpson Marine Stewardship Council
This is really great news?
"This is really great news," he said. "We have done an assessment of the entire inshore industry and it's clear that cod is on the way back."
The recovery was thanks to strict catch limits aided by a massive public campaign for sustainable fish, he said.
Barrie Deas, the chief executive of the National Federation of Fishermen's Organisations, which represents fisherman in England, Wales and Northern Ireland, told Radio 4's Today programme it was a "dramatic turnaround".
"I think a major part of it is there are fewer vessels out there. There have been big decommissioning schemes.
"There's also been a change in the mindset in the industry. We work very closely with the scientists now."
Despite the positives, the MSC admits to an unwanted side-effect to the campaign against cod-eating.
Some celebrity chefs have pointed people towards red gurnard as an alternative.
This used to be caught as a bycatch, but so many fishermen are now hunting red gurnard that it is possible stocks of that might run low.
The data on red gurnard was so poor that it is impossible to tell whether it's sustainable or not, the report says.
Brown crab falls into the same category.
The report calls for investment in stocks, such as red gurnard, to ensure they are sustainably managed.
The MSC's Claire Pescod said: "There's been a significant interest in underutilised species over the past few years.
"When those fish suddenly become commercially popular, we need to put a lot more effort into providing the appropriate information for their management to make sure that they are managed sustainably."
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