Public Health Warning - For collection and eating of shellfish

10 August 2018

A public health warning has currently been issued covering the area whole Taranaki Coastline as this area has been affected by a Marine Biotoxin Bloom. 

Recent testing of the shellfish in this area has shown elevated levels of paralytic shellfish poisoning (PSP) toxin.  At the present levels of toxin it is unlikely that people would suffer illness unless they had eaten a large amount of shellfish.

Paralytic Shellfish Poisoning is caused by eating shellfish contaminated with toxin produced by toxic algae.  Scallops, mussels, oysters, pipi, tuatua and other bi-valve shellfish are the main vehicles of transmission, but illness may follow consumption of crabs, lobsters, crayfish, paua and other seafood, especially if the gut is eaten.  Cooking does not destroy the toxin.

Symptoms usually occur within 12 hours of eating shellfish containing the toxin. Below is some further information about PSP. 

Some general information about paralytic shellfish poisoning:

  1. The onset of symptoms is typically within 30 minutes post-ingestion (median 2 hours).
  1. The earlier the onset of symptoms, the more severe the illness. Children may be more susceptible than adults.
  1. Effects are initially seen as paraesthesia in and around the mouth. This spreads to the face and neck, and may be followed by weakness and paralysis of limbs. Nausea, vomiting, and diarrhoea are reported, and a sensation of floating is frequently experienced. Death may occur due to respiratory paralysis, the most concerning aspect of this poisoning. Central nervous system depression is not characteristic of saxitoxin exposure.

Severity of Poisoning


Mild Saxitoxin Toxicity

Moderate Saxitoxin Toxicity

Severe Saxitoxin Toxicity

Perioral/lingual numbness and tingling

Paresthesia of the face and neck
Nausea and vomiting
Sensation of floating

Weakness of arms and legs
Respiratory depression
Limb paralysis
Respiratory paralysis


Paralytic shellfish poisoning is a notifiable disease so please let us know if you have a suspected case.  It is helpful if the patient is asked to retain samples of the suspect shellfish for analysis.

Further information can be found at:

Or contact the On-Call Health Protection Officer for Taranaki Public Health on 06 753 7798.

Last updated: Monday, August 13, 2018

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