People are being warned not to collect shellfish in the Kaipara Harbour due to elevated toxin levels in the fish, the Ministry of Primary industries says.
Tests taken from shellfish in the Harbour are showing Paralytic Shellfish Poisoning (PSP) toxins above the safe limit of 0.8 mg/kg set by MPI.
"Anyone eating shellfish from the area is potentially at risk of illness" the regulator said Tuesday.
"Mussels, oysters, tuatua, pipi, toheroa, cockles, scallops, catseyes, kina (sea urchin) and all other bivalve shellfish should not be eaten,"
Symptoms of food poisoning typically appear between 10 minutes and 3 hours after consumption and may include numbness and a tingling (prickly feeling) around the mouth, face, and extremities (hands and feet).
Difficulty swallowing or breathing, dizziness, headache, nausea, vomiting and diarrhoea may also indicate exposure.
In severe cases, paralysis and respiratory failure and even death can occur, the ministry says.
The warning covers the whole harbour up to the entrance from Oneone Beach to North Head.
If you get sick after eating shellfish from the region, call Healthline at 0800 61 11 16 or get immediate medical help. Contact your local public health unit and save leftover shellfish for testing.
Toxin levels will be monitored continually and MPI will report when the seafood is again safe to eat.
MPI says it monitors water and flesh of commercially harvested shellfish sold in stores and exported.
