People are being advised not to collect or eat shellfish in parts of the Bay of Plenty and Waikato regions after routine tests found levels of shellfish toxins above the safe limit.
The Ministry for Primary Industries (MPI) issued the public health warning yesterday and said anyone eating shellfish from the affected area was potentially at risk of illness.
The warning was in place from Te Ororoa Pt, just north of Tairua, down to Bowentown Heads but not including Tauranga Harbour.
The ministry said in a press release that tests on shellfish samples taken from that region showed levels of Paralytic Shellfish Poisoning (PSP) toxins above the safe limit of 0.8 mg/kg.
"Mussels, oysters, tuatua, pipi, toheroa, cockles, scallops, catseyes, kina [sea urchin] and all other bivalve shellfish should not be eaten."
The ministry said cooking shellfish did not remove the toxin.
"Pāua, crab and crayfish may still be eaten if the gut has been completely removed prior to cooking, as toxins accumulate in the gut. If the gut is not removed its contents could contaminate the meat during the cooking process."
Symptoms typically appear between 10 minutes and three hours after ingestion and may include:
•numbness and tingling (prickly feeling) around the mouth, face, and extremities (hands and feet)
•difficulty swallowing or breathing
•paralysis and respiratory failure and in severe cases, death.
The ministry said the monitoring of toxin levels would continue and any changes would be communicated accordingly.
"Commercially harvested shellfish – sold in shops and supermarkets, or exported – is subject to strict water and flesh monitoring programmes by MPI to ensure they are safe to eat."
It said if anyone becomes ill after eating shellfish from an area where a public health warning has been issued, they should phone Healthline for advice on 0800 61 11 16, or seek medical attention immediately.
"You are also advised to contact your nearest public health unit and keep any leftover shellfish in case it can be tested."