New Zealand Food Safety (NZFS) has extended an existing shellfish biotoxin warning from Cape Kidnappers up to East Cape.
Latest testing of mussels from Tolaga Bay had shown the biotoxins had risen “dramatically”, said NZFS deputy director-general Vincent Arbuckle.
“We particularly want to draw people’s attention to the fact that levels of these toxins are increasing and in the latest results from Tolaga Bay mussels have risen substantially to 11 times over the safe limit.
“Consumption of shellfish containing these toxins can cause serious illness, including death. Cooking the shellfish does not remove the toxin.”
The initial alert advised the public not to collect or consume shellfish gathered from the Northland east coast because of paralytic shellfish toxins.
Routine tests on mussels from Houhora had shown levels of paralytic shellfish toxins over the safe limit, Mr Arbuckle said.
The warning extended from Cape Karikari north to Kokota (the Sandspit), just south of Parengarenga Harbour.
“The current warning in Hawke’s Bay has now been extended from Cape Kidnappers right up to East Cape.
As algal blooms increased in size, the levels of toxins in shellfish could reach higher levels, Mr Arbuckle said.
“Please do not gather and eat shellfish from these affected areas because anyone doing so could get seriously sick.
“Cooking the shellfish does not remove the toxin, so shellfish from these areas should not be eaten.”
Symptoms of paralytic shellfish poisoning usually appear within 10 minutes to three hours of eating and may include numbness and a tingling (prickly feeling) around the mouth, face, hands, and feet, difficulty swallowing or breathing, dizziness and headache, nausea and vomiting, diarrhoea, paralysis and respiratory failure and, in severe cases, death.
Pāua, crab and crayfish may still be eaten if the gut has been completely removed before cooking, as toxins accumulate in the gut. If the gut is not removed, its contents could contaminate the meat during the cooking process.
Finfish are not affected by this public health warning.
NZFS has had no notifications of associated illness.
If anyone becomes ill after eating shellfish from an area where a public health warning has been issued, phone Healthline for advice on 0800 61 11 16, or seek medical attention immediately. People are also advised to contact the nearest public health unit and keep any leftover shellfish in case it can be tested.
“NZFS is monitoring shellfish in the region and will notify the public of any changes to the situation,” Mr Arbuckle said
Commercially harvested shellfish — sold in shops and supermarkets or exported — is subject to strict water and flesh monitoring programmes by NZFS to ensure they are safe to eat.