Risk assessment of the Scottish monitoring programme for the marine biotoxins in shellfish harvested from classified production areas: Review of the current sampling scheme to develop an improved programme based on evidence of risk

The aim of this study was to assess the Scottish inshore monitoring programme for biotoxins in shellfish from classified inshore production areas in Scotland. This programme,conducted by Food Standards Scotland (FSS), aims to determine the prevalence of paralytic shellfish toxin (PST) (responsible for paralytic shellfish poisoning (PSP)), domoic acid (DA) (responsible for amnesic shellfish poisoning (ASP)), and lipophilic toxins (LT) (some of which are responsible for diarrhetic shellfish poisoning (DSP)). These are produced by certain types of phytoplankton, such as Alexandriumspp., Pseudo-nitzschiaspp., Dinophysisspp., Phalacroma rotundatum(until recently included within theDinophysisgenus), Azadiniumspp. and Prorocentrum lima, and these toxins then accumulate in shellfish. Shellfish harvesting areas in Scotland have been assigned to larger groups, called pods. The current FSS monitoring programme (as implemented in 2012) consists of a combination of monthly, fortnightly and weekly monitoring of biotoxin levels in shellfish sampled from these pods. For about half the pods, data on potentially biotoxin-producing phytoplankton arealso collected regularly. In this study, the biotoxin patterns observed in shellfish across Scotlandthroughout the year were established using data collected over a fifteen-year period from April 2001 to September 2015. These data were compared with corresponding phytoplankton data to assess relationships between the biotoxin patterns and abundance of the phytoplankton genera responsible for the biotoxin of interest.The current FSS monitoring programme was assessed for the risk of a toxic event at a particular location being undetected. Alternative schemes that offered a more targeted allocation of resources or an improved level of public health protection were also considered.