The British are developing an increasing enthusiasm for less familiar species of chilled fish, belying the notion of conservative shoppers who only want cod and haddock.
Supplier New England Seafood has reported rocketing sales of several species, notably monkfish, halibut, red snapper, sea bream, and gilthead bream.
Swordfish from managed fisheries and tilapia have also been doing well.
Dan Aherne, managing director, said that sales of yellowfin tuna and MSC-certified wild Alaskan salmon had also been "phenomenal", with volumes now significant, and there was enthusiastic take-up for farmed sea bass. Stocks of European wild sea bass are under pressure. Aherne said he was particularly pleased with the success of mahi mahi, which has a significant presence in the UK for the first time this spring.
"We have brought in 25 tonnes of mahi mahi so far and there has been very good uptake. of it.
"Consumers are finding that preparing and cooking these species of fish is in fact not as complicated as they been led to believe. They find this is particularly the case with tuna steak, which is cooked in exactly the same way as a fillet steak.
"But shoppers are also behind us because of all the press stories about fisheries management."
Aherne said that another key factor in sales of less familiar species was a growing recognition by supermarkets that seasonality was key to sustainability.
"They weren't that well geared to it at once but now they are very pro."
New England Seafood has ambitious plans for growth. The £40m turnover Chessington-based company has been annually growing sales by an average of 30% and plans to establish two more plants within five years.