Asda is the only one of the big four retailers to have shown a year-on-year decline in sales of chilled fish over the past year, according to data from Kantar Worldpanel.

Value sales of chilled fish at Asda have fallen 0.3% and volumes have slipped 0.5% [52w/e 8 August]. Sales at Tesco have risen 5.7%, however, while Sainsbury's sales increased 1.9% and Morrisons 3.8%.

It is also the only one of the big four to have seen its chilled fish market share decrease, from 8.8% to 8.6% in terms of value sales and from 9.7% to 9.6% in volume.

Although sales were down over the 52-week period, Asda's chilled fish sales have improved recently value sales have grown 2.1% in the 12 weeks to 8 August and by 18.2% over the past four weeks.

It claimed it had seen "significant" uplifts in the past quarter as a result of a two-for-£4 offer. It had also introduced pesto-topped salmon fillets, chilli coriander Patagonian scallops and butterfly trout with pea and mint, which it claimed had resonated well with consumers. Asda's performance stands in contrast to the 1% growth it experienced in ­total fresh grocery sales over the 52-week period. One supplier said Asda's year-on-year sales decline was a symptom of its strong focus on low prices. "If the price message is too blatant or fish is perceived as 'cheap', then they suspect the quality, regardless of the reality," he said. Another source claimed fresh fish was not a priority for Asda. "Those in the lower-income bracket that Asda targets are not particularly interested in fresh fish."

Asda rejected this, saying it sourced all its fish responsibly and focused as much on freshness and quality as it did on "market-leading prices".

At the other end of the pricing spectrum, Waitrose's fresh fish sales were up 13.6% by value and 11% by volume, according to Kantar [52w/e 8 August].

"We have made it really easy for customers to buy fish and cook it, and it delivers fantastic results," said Jeremy Ryland Langley, specialist buyer for fish and shellfish at Waitrose.