Shellfish biotoxin alerts

Shellfish biotoxin warning for Western Firth of Thames

Reason for alert	Paralytic Shellfish Poisoning (PSP) Check the symptoms of PSP
Date warning issued	2 May 2025 Media release: Shellfish biotoxin warning for Western Firth of Thames
Affected area	The warning extends from the mouth of the Waitakaruru River up to Pakatoa Island and across to the mid-point of the Firth as per the attached map.
Shellfish affected	Affected shellfish include bivalve shellfish such as mussels, oysters, tuatua, pipi, toheroa, cockles and scallops, as well as pūpū (cat’s eyes) and Cook’s turban. Note, cooking shellfish does 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. Kina and finfish are not affected by this warning.
Symptoms	Symptoms typically appear between 10 minutes and 3 hours after ingestion 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 diarrhoea paralysis and respiratory failure and, in severe cases, death.
Other information	Paralytic shellfish toxins have been detected in shellfish at levels over the safe limit of 0.8mg/kg set by New Zealand Food Safety. Ongoing testing will continue, and any changes will be communicated accordingly. No other warnings are currently in place

Map — Affected area from the mouth of the Waitakaruru River up to Pakatoa Island and across to the mid-point of the Firth.

Public warnings about toxic shellfish

We test shellfish and seawater for toxic algae every week from popular shellfish gathering areas around New Zealand. If the shellfish are not safe to eat, we issue public health warnings and put up signs at affected beaches.

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If you get sick after eating shellfish

If someone gets sick after eating shellfish, make sure you:

phone Healthline for advice on 0800 61 11 16, or get medical help immediately
advise your nearest public health unit
keep any leftover shellfish in case it can be tested.

Find your nearest public health unit – Ministry of Health

Safety of commercially sold shellfish

The warnings on this page are only for recreational shellfish that people can collect themselves. The warnings do not apply to shellfish that you can buy from shops or supermarkets, or shellfish for export.

We have strict water and flesh monitoring programmes for commercial shellfish to ensure it's safe to eat. If commercial shellfish become toxic, the shellfish cannot be harvested or sold, and the growing areas are closed.