The Northland District Health Board's Public Health Unit's warning against collecting or eating shellfish from the region's west coast has been extended to include the Hokianga Harbour and north to Tauroa (Reef) Point.
Shellfish collected within that area have shown levels of Paralytic Shellfish Poisoning (PSP) toxins significantly above the regulatory level.
The symptoms of paralytic shellfish poisoning include numbness and tingling around the mouth, face or extremities, difficulty in swallowing or breathing, dizziness and double vision. In severe cases paralysis and respiratory failure can occur within 12 hours.
"Cooking the shellfish does not remove the toxin," Northland Medical Officer of Health Dr Jose Ortega Benito said. "Anyone who becomes ill after eating shellfish should see a doctor or phone Healthline (0800 611-116) for advice. In an emergency phone 111 for immediate medical help."
The DHB would continue to monitor the situation, and would advise of any changes, he added, while anyone with questions was welcome to call Whangarei Hospital on (09) 430-4100 and ask for the on-call Health Protection Officer.
Maps and updates were also available at www.mpi.govt.nz/travel-and-recreation/fishing/shellfish-biotoxin-alerts/