Environment Southland’s latest monitoring has found elevated levels of toxic algae at the Waiau River near Excelsior Creek, downstream of the Mararoa Weir.
Toxic algae 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, run-off into waterways, a sudden increase in temperature and low flows.
River users and animals should avoid contact with algal mats and remain alert in other parts of the river for algal growth or mats of algae floating in the water.
These algae can produce toxins that are harmful to people and animals if swallowed, or through contact with skin.
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.
