Shellfish harvesting in Shetland has been suspended after unusually high levels of toxins were detected in shellfish traced back to Scottish manufacturer Shetland Mussels.

An outbreak of shellfish poisoning in the South East of England between 13 and 15 July has been traced back to the Scottish manufacturer, which provides shellfish to a range of restaurants in the region.

The 70 people who displayed symptoms consistent with diarrheic shellfish poisoning reported illness after eating at restaurants in Covent Garden, Holborn, Clapham, Bromley, Blackheath, Reading, Hampshire and Richmond.

“This is the first time that we have experienced a problem with customer illness in our 16 years of production”

Michael Tait, Shetland Mussels

FSA testing revealed higher than normal levels of toxins in shellfish in the area, which has now been closed as a precautionary measure. The industry has voluntarily suspended all commercial harvesting from the waters around Shetland until the toxin levels subside.

Shellfish toxins are produced by naturally occurring marine phytoplankton, and detected levels are higher in summer months. The FSA has a sampling programme that regularly monitors shellfish harvesting.

“This is the first time that we have experienced a problem with customer illness in our 16 years of production,” said managing director of Shetland Mussels Michael Tait.

“The rate of increase in the phytoplankton levels, which are naturally occurring in the sea at this time of year, is unprecedented and has not been seen at any of our harvest sites before. We have been proactive in working with the customers and the authorities in investigating this incident.

“We understand the elevated risk of toxins in the summer months and have a HACCP-based approach to manage this risk, which our local environmental health officers and external auditors have approved. Unfortunately and regrettably, the unprecedented increases seen here meant the toxin levels increased within the timeframe between samples.

“We will therefore fully review our systems prior to commencement of harvesting to ensure that if the same circumstances occur again in the future, there will be no risk to consumers.”

The FSA is reminding all UK companies involved in the sale of shellfish to ensure that biotoxin risks are taken into account in their food safety management systems.