Restaurants have taken a popular fish off the wedding banquet menu - the latest reaction to the series of contamination scares which the fish trade says is costing it $1 million a day. Sales of all marine fish were down 30 per cent yesterday after a sample of green grouper from a Wellcome supermarket was found to contain the cancer-causing fungicide malachite green. The supermarket chain removed green grouper from sale at 24 other stores after the find. 'Green grouper has always been a popular dish in wedding banquets. Those from Taiwan are particularly prized, as the flesh tastes better than those from Thailand,' said Thomas Woo Chu, managing director of Hsin Kwong Restaurant Holdings, which has suspended the sale of the fish. 'We will replace the dish [at no extra charge] for those who have ordered green grouper for their banquets, and we will shoulder the losses,' he said. Other restaurants have shifted the burden to the wholesalers or to customers. 'A restaurant has asked one of our members to replace 120 green grouper with the more expensive coral grouper at his own expense,' Aberdeen Fisheries and Seafood Association vice-chairman Lee Choi-wah said. 'That wholesaler suffered a loss of more than $20,000.' Mr Lee said the industry's losses were running at more than $1 million a day. Association chairman Chan Fu-ming said the scare was not confined to green grouper. 'Trade in all marine fish has fallen 30 per cent,' he said. 'Wholesalers will reduce the amount of their purchases tomorrow.' Kinson Ho King-sing, managing director of the Tai Wu restaurant chain, said customers who held banquets at its restaurants would have to pay extra to change dishes. 'Customers are worried about all sorts of grouper now. More than 60 green grouper dishes were replaced yesterday. We changed it to lobster or coral grouper at their request. Most are willing to pay extra,' he said. Mr Ho said his staff would eat the chain's remaining stock of green grouper for lunch in the next few days.