Dar seafood ppp standard

Chemical contaminants

The chemical contaminants discussed here are algal biotoxins, histamines, ciguatoxins, escolar wax esters, arsenic, cadmium, lead, mercury and zinc.

Algal biotoxins

Algae form an important component of the plankton diet of shellfish such as mussels, oysters and scallops. Molluscan shellfish may accumulate toxins produced by toxic algae or other marine micro-organisms, and these may present significant human health risks. Shellfish generally become toxic following a hazardous algal bloom where toxigenic species reach high levels in the water. Of the estimated 2000 living dinoflagellate species, about 30 species produce toxins that can cause human illness from shellfish or fish poisoning. When humans eat seafood contaminated by these toxins, they may suffer a variety of gastrointestinal and neurological illnesses. The most common syndromes are:

• 
  paralytic shellfish poisoning
  
• 
  diarrhoeic shellfish poisoning
  
• 
  neurotoxic shellfish poisoning
  
• 
  amnesic shellfish poisoning.
  
  
  

In addition to these classes of algal biotoxins, azaspiracids (AZAs) are recently identified cytotoxins which have been found in Northern European mussels (specifically in Ireland, United Kingdom and Norway), causing a diarrhoeic shellfish poisoning-like acute toxic response in a small number of outbreaks of food-borne illness. There is no evidence that AZAs are found in Australian or New Zealand shellfish, and although some risk might occur due to imports (for example, mussels from the United Kingdom), these toxins have not been explicitly considered in this report.