Oyster mortalities reported in ten Irish bays

Initial reports came from three bays in the south-west, south east and north-east where oysters were imported from France earlier this year.

Reports have now been received from a further seven bays where seed or partially grown oysters were imported from France, as well as England and Guernsey. Oysters that were in deeper water and growing more quickly appear to have been more severely impacted.  

 Four samples from three bays have tested positive for herpes virus OsHV1. Analysis is ongoing.. All movements of oysters must be notified to the Marine Institute and will be reviewed on a case by case basis. Movements will be restricted from areas experiencing oyster losses. 

Some oyster growing areas in France, where mortalities began in April, continue to experience oyster mortalities. They began in south of France and spread affecting the majority of French growing areas. 

The herpes virus, which is considered to be endemic in parts of Europe, is not controlled under fish health legislation. Therefore when importing seed or partially grown oysters, it is the responsibility of the producer to ensure that their stock is free of the herpes virus.