Officials examine mussels produced in Shengsi county, Zhoushan, East China's Zhejiang province. [Photo/thehour.cn]

Mussels produced in Shengsi county, Zhoushan are still edible despite an alert issued by the local government earlier this month that some mussel samples were found to contain excessive toxins.

Shengsi issued a consumption alert on July 7 that mussels produced in the county may contain excessive toxins, which are believed to be caused by red tide. 

Some mussels may be toxic, but that doesn't mean all of them are inedible, according to experts, revealing that even the "toxic" mussels will see their toxin levels drop to an acceptable level a few days after the red tide.

Red tide occurs in Shengsi every year and usually lasts for a week or several weeks from mid-May to mid-July. 

Chen Bo, an official from the Shengsi food safety commission, said that 33 samples drawn from the city's eight breeding areas a few days after the issuance of the alert showed that they all meet national food safety standards. 

Qualitative tests have also been done on 25 batches of wild mussels being sold at markets in the county, with all of them testing negative.

Mussels from all breeding areas in Shengsi have been tested, as have all of the most common shellfish species sold on the market. 

Chen said that more efforts should be made to ensure that all shellfish on the market is safe to eat. 

Mussels are a common delicacy in East China's Zhejiang province during the fishing moratorium. Located in Zhoushan, an island city in Zhejiang, Shengsi has been dubbed the "home of mussels in China" for large shellfish production.