Figure 1. Surveillance of flat oysters, Ostrea edulis , and blue mussels, Mytilus spp, in Norway cover wild populations and shellfish farms along the south and west coast, north to Trøndelag, according to a plan communicated with the Norwegian Food Safety Authority. In 2021 one oyster population in Agder was inspected (orange), one commercially exploited wild population In Rogaland and one oyster lagoon (nursery) was inspected and sampled (yellow). One mussel farm was sampled (blue). In addition to the surveillance programme we study the distribution of Marteilia pararefringens in mussels. Several sites along the west coast were sampled in 2021. The red circles indicate sites where M. pararefringens have been detected.
