Shellfish Sampling

To ensure the health status of live bivalve molluscs, such as oysters, cockles, mussels, clams and razor fish from naturally occurring and farmed estuarine and marine stocks, Port Health Authorities are involved in the Classification, monitoring shellfish beds and the movement of shellfish.

Officers will regularly sample species that are resident with their jurisdiction for microbiological examination to determine the health status of the shellfish. Before shellfish can be gathered commercially and placed on the market for human consumption, each shellfish bed must be ‘Classified’, dependent upon the health status of the shellfish.


Bed Classification E. Coli presence /100G Flesh Effect upon the bed
A ≤ 230 E. coli/100g Molluscs can be harvested for direct human consumption
B 90% of samples must be ≤ 4600 E. coli/100g; all samples must be less than 46000 E. coli/100g. Molluscs can be sold for human consumption:
  • after purification in an approved plant, or
  • after re-laying in an approved Class A re-laying area, or
  • after an EC-approved heat treatment process.
C ≤ 46000 E. coli/100g Molluscs can be sold for human consumption only after re-laying for at least two months in an approved re-laying area followed, where necessary, by treatment in a purification centre, or after an EC-approved heat treatment process.


In all cases, the health standards in Annex III of EC Regulations 853/2004 and the microbiological criteria adopted under EC Regulation 2073/2005 must be met.  Molluscs must not be subject to production or collected in prohibited areas.