The Ministry for Primary Industries (MPI) has issued a public health warning advising the public not to collect or consume shellfish harvested between the Mohaka River mouth and Cape Kidnappers.
Routine tests on shellfish samples taken from the region show levels of Paralytic Shellfish Poisoning (PSP) toxins above the safe limit of 0.8mg/kg set by the Ministry.
"Anyone eating shellfish from this area is potentially at risk of illness," the warning states.
Mussels, oysters, tuatua, pipi, toheroa, cockles, scallops, catseyes, kina and all other bivalve shellfish should not be eaten, and cooking shellfish does not remove the toxin.
Paua, 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."
Snapper, gurnard and tarakihi are not affected by the algae and are still safe to eat.
Commercially harvested shellfish sold in shops and supermarkets are subject to strict water and flesh monitoring programmes by MPI to ensure they are safe to eat.
In June last year, locals were warned not to consume shellfish found between Whareongaonga and Mohaka River because of dangerous toxins.
Symptoms typically appear between 10 minutes and three hours after ingestion, and may include numbness and a tingling/prickly feeling around the mouth, difficulty swallowing or breathing, dizziness, headache, nausea, vomiting, diarrhoea, paralysis, respiratory failure and, in severe cases, death.
-If anyone becomes ill after eating shellfish from an area where a public health warning has been issued, phone Healthline on 0800 61 11 16 or seek medical attention immediately.