Blue-green algae bloom strikes at Kaitaia

A seasonal blue-green algae bloom in Kaitaia’s sewage treatment ponds is compounding drought problems and could pose a risk to the health of both people and stock.


Farmers are being warned not to take water for stock from the Awanui River downstream from the treatment ponds which discharge to the stream.


Water & Wastewater Operations Manager Jim Brooks says the council will be supplying tankered water to the three affected properties downstream of the treatment plant at Bonnett Road as a precautionary measure and is recommending that people should not swim or allow their pets to drink from that part of the river.


Mr Brooks says the council has a weekly sampling regime to check algal counts in the ponds and this week’s tests had indicated levels that could be considered a risk to health. Blue-green algae blooms were last found in the ponds at high concentrations in 2007.


The algae are present in almost all water ecosystems including creeks, rivers, lakes and wetlands. They multiply rapidly and bloom when conditions are right. They can be common at this time of the year when sunlight encourages vigorous growth.


The toxins they produce can cause allergic reactions, skin rashes, irritation of the eyes and tummy upsets. In extreme cases they can cause nerve and liver damage.