Marine biotoxin alerts

Shellfish and seawater samples around New Zealand are tested each week to ensure they are not contaminated with biotoxin from blooms of algae. Public warnings are issued when shellfish are not safe to eat. This page contains information relating to the non-commercial (recreational and traditional) taking of shellfish only.

This page is updated as soon as new information comes to hand. All the warnings on this page are current and remain in force.

Marine biotoxin warnings currently in force

North Island

North Island contaminated areas

Hokianga Harbour

The Health Protection Unit of Northland District Health Board continues to advise people not to consume shellfish from the Hokianga Harbour. This public health warning has been issued due to the persistence of Microcystin Toxins above safe levels in shellfish.

Shellfish in the Hokianga Harbour were tested for Microcystins after a bloom of toxic Cyanobacteria occurred in Lake Omapere which drains into the Hokianga Harbour.

High levels of microcystins are frequently associated with the death of animals consuming contaminated water. Human deaths from consumption on microcystins have not been well reported but it is acutely toxic in animal studies and they are thought to cause liver damage in humans. Human fatalities have also occurred when water used for dialysis of patients with kidney failure has become contaminated.

For further information contact: Northland District Health Board (09) 430 4100

Bay of Plenty

13th January 2012

Following ongoing shellfish toxin monitoring the Paralytic Shellfish Poisoning (PSP) toxin warning has been extended eastwards to include Whakatane Heads.

The affected area now includes the entire coastline from Tairua (including Tairua Harbour), east along the Bay of Plenty coastline, including Tauranga Harbour, Maketu and Waihi estuaries, to Whakatane Heads. Also included in the warning are Matakana and Motiti islands, and all other inshore islands along this coastline.

The health warning applies to all bi-valve shellfish including mussels, pipi, tuatua, cockles, oysters, scallops as well as catseyes and kina (sea urchin). Shellfish in the affected area should not be taken or consumed. Paua, crayfish and crabs can still be taken but as always, the gut should be removed before cooking.

Consumption of shellfish affected by the paralytic shellfish toxin can cause numbness and tingling around the mouth, face or extremities; difficulty swallowing or breathing; dizziness; double vision; and in severe cases, paralysis and respiratory failure. These symptoms usually occur within 12 hours of a person consuming affected shellfish. Anyone suffering illness after eating shellfish should seek medical attention.

Monitoring of toxin levels will continue along the coast and any changes will be communicated accordingly.

For all health warning updates across the Bay of Plenty and Lakes districts call 0800 221 555.

For more information please contact:

Dr Neil de Wet
Medical Officer of Health
Toi Te Ora – Public Health Service
Ph: 0800 221 555

For Waikato/Coromandel

Health Protection Officer
Population Health, Waikato District Health Board
Phone 07 838 2569
After Hours –
On-Call Health Protection Officer 021 999 521
On-Call Medical Officer of Health 021 359 650

South Island

There are no biotoxin warnings currently in place.

There are currently bacteriological water quality issues for the Christchurch area which are not related to toxic algae. Please check with your local health protection officer regarding this.

Please note:

Warnings about unsafe areas are subject to change. The public should contact their local health protection officers at District Health Boards if they are in doubt about where they should take shellfish.

Public health unit contacts