Filter-feeding shellfish, especially mussels, oysters and pectinids (scallops, scallops…), can accumulate toxins produced by microalgae in their body. These toxins can, for example, develop in micro-algae in the event of significant sunlight. : the increase in water temperature and light are indeed growth factors.
When they are contaminated by the toxins of these algae, these shellfish become toxic to humans, due to their action potentially paralyzing. These paralyzing toxins are also called PSP which comes from the English : “Paralytic Shellfish Poisoning“.
They quickly cause, after ingestion of contaminated shellfish, a paresthesia (disorder of the sense of touch, multi symptoms : tingling, tingling, numbness, etc.) brutal (in 5 to 30 min) lips, of the face, arms and legs. Serious cases are reported with motor incoordination, incoherence, and a risk of death from respiratory paralysis. This poisoning is not contagious.
The standards are 800 µg/kg saxitoxin.
Ingestion of contaminated shellfish, consult your doctor or the nearest poison control center in your area.