Food safety authorities in Shanghai are striving to enforce a ban on the sale of a wide range of aquatic products to help prevent outbreaks of disease.

Local regulations restrict the sale of certain categories of products, "but these regulations can contradict each other and need integrating", said Gu Zhenhua, deputy director of the city's food safety agency.

The agency will list all the banned products in catalogue form to help law enforcers co-ordinate actions.

The move follows recent food safety scares over the use of waste industrial gelatin in food and pharmaceutical products.

Certain to be included in the catalogue is the clam, Scapharca subcrenata, believed to have been the cause of a major outbreak of hepatitis A in Shanghai in 1988, affecting more than 300,000 people. River shrimps, soaked in wine before been eaten live, will also be on the list.

Some products, such as crab paste will face seasonal bans.

Sashimi will not be listed, the agency said, as long as quality and processing meet hygiene standards.

The list will be posted online and violations will carry a heavy fine.

But Scapharca subcrenata, is still a popular dish, favored by many Shanghai residents, and restaurants have been found selling it as dried scallop.

On Thursday, the clam, was secretly traded for 45 yuan ($ 7.13) per kilogram at the Tongchuan Road wholesale market for aquatic products in the Putuo district of Shanghai.

A vendor named Li told China Daily he sold it mainly to small restaurants and some families.

An online poll by the news website eastday.com on Thursday showed that most people disapproved of the ban. Many said the product should be retained on the food menu after the government sets strict safety standards.

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