Toxic algae found in the Waiau River at Tuatapere

UPDATE 24/1/2019: Levels of toxic algae in the Waiau River at Tuatapere are now below alert levels. People are encouraged to remain vigilant as toxic algae species are still present, although at low levels.


These algae can produce toxins that are harmful to people and animals if swallowed, or through contact with skin. People and animals (dogs in particular) should avoid contact with the Waiau River and be mindful of the potential health risks, until health warnings are removed.

If you experience health symptoms after contact with contaminated water, visit a doctor immediately. If you are concerned that any animals have consumed toxic algae or contaminated water, they should be taken to a vet immediately.

Benthic cyanobacteria can be recognised at rivers and streams as a green/brown slime on rocks, or dark brown/black mats at the water’s edge. Several factors can contribute to the growth of toxic algae, such as high levels of nutrients or sediment run-off into waterways, a sudden increase in temperature, and low flows.

Environment Southland monitors toxic algae monthly at a number of river and lake sites across Southland.

For further information visit Environment Southland’s website www.es.govt.nz/toxic-algae.