Health Alerts and Warning Messages

Public Health Warning

Click here for all current Northland health warning messages.

Shellfish

Click here for all current Shellfish Biotoxin Alerts

How can I be sure the shellfish (kai moana) I am gathering is safe to eat?
Shellfish (kai moana) tend to concentrate any pollution of the surrounding water in their flesh, so special care should be given when gathering shellfish to avoid getting sick. Seawater may become polluted with bugs (bacteria) or viruses from run-off after rainfall (for example from surrounding farmland), or from failing septic tanks or animal-contaminated nearby streams. These bugs and viruses can cause vomiting and diarrhoea. 

Shellfish may also be contaminated with marine biotoxins from certain types of algal blooms in the seawater. Biotoxins can cause a range of illnesses from vomiting and diarrhoea to nervous system problems like headaches, numbness and tingling, seizures and coma.

A further risk factor is that shellfish are often eaten raw or only partially cooked - which may not kill the polluting bugs. Cooking shellfish does not destroy biotoxins from algal blooms.

To avoid collecting shellfish that could make you sick, Public Health advises you to collect only from visibly clean seawater with no potential contamination from sources of human or animal sewage.

We advise you NOT to collect shellfish:

• A few days after heavy rainfall where the seawater looks muddy or cloudy. This may mean the water is carrying high numbers of bugs (bacteria and viruses). If human sewage is possibly contaminating the rainfall-runoff, then shellfish should not be collected within a month of the rainfall. It takes this long for shellfish to clear themselves of viruses. Only the bacteria clear within a few days.
• Near stream outlets where animals such as cows and sheep could be wading in and polluting the water;
• Near houses, baches, drains on the beach or any other potential source of human sewage. The seawater could be contaminated with sewage from septic tanks or stormwater from these sources;
• Near any official signs indicating the seawater is contaminated (for example, from marine biotoxins or accidental sewage discharge).

Areas known to be affected by biotoxin contamination have warning signs placed nearby, or on beach access points, and are also advertised on the radio and in the newspapers. Please be aware that cooking shellfish does not destroy biotoxins from algal blooms.

Click here for general information on safe shellfish collection.