Monkfish is set to return to Asda shelves just three months after the supermarket removed it because it was not considered a sustainably caught species.
Scottish fishermen hailed the u-turn as a victory and a vote of confidence in the way they have managed Scotland's small but valuable monkfish quota.
The Shetlands fishery produces 15-20% of the UK's monkfish catch and provides a vital £15m economic boost to the islands.
A spokeswoman for Asda said the change of policy had come about because the Marine Conservation Society had taken monkfish from northern fisheries off its black list of endangered stocks. "It means we can buy monkfish from northern fisheries, such as those off Scotland," she said. "It's too early to say when it'll go back on shelves because we need to find a supplier."
An MCS spokeswoman said scientific evidence suggested there had been a "significant increase" in the abundance of the stock over the past five years.