Public health warning for shellfish

File photo: Getty Images
File photo: Getty Images
New Zealand Food Safety (NZFS) is advising the public not to collect or consume shellfish from Christchurch beaches and Lyttelton Harbour due to the presence of diarrhetic shellfish toxins.

"Routine tests on greenshell mussels from Sumner have shown levels of diarrhetic shellfish toxin over the safe limit," NZFS deputy director-general Vincent Arbuckle said.

Affected shellfish include bivalve shellfish such as mussels, oysters, tuatua, pipi, toheroa, cockles and scallops, as well as pūpū (cat's eyes), Cook's turban and kina (sea urchin).

The warning extends from Waimairi Beach to the southern head of Lyttelton Harbour (Adderley Head). The affected area includes Lyttelton Harbour and the Avon and Heathcote River Estuary.

"Please do not gather and eat shellfish from this area because anyone doing so could get sick," Arbuckle said.

"Cooking the shellfish does not remove the toxin, so shellfish from this area should not be eaten."

Symptoms of diarrhetic shellfish poisoning usually appear within 30 minutes of eating and last for about a day. These can include: diarrhoea, vomiting, nausea and abdominal cramps.

If anyone became ill after eating shellfish from an area where a public health warning has been issued, they should contact Healthline on 0800 61 11 16, or seek medical attention immediately.

People should also contact their nearest public health unit and keep any leftover shellfish in case it can be tested.

Arbuckle said pāua, crab and crayfish could be eaten if the gut had been completely removed prior to cooking, as toxins accumulated in the gut. If the gut was not removed, its contents could contaminate the meat during the cooking process.

"Finfish are not affected by this public health warning, but we advise gutting the fish and discarding the liver before cooking."

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.

NZFS was monitoring shellfish in the region and would notify the public of any changes.