Toxic algae found at Waikaia River

Media Release

22 February 2023

Environment Southland’s latest monitoring has found elevated levels of toxic algae in the Waikaia River, at Waikaia.

Potentially toxic algae (benthic cyanobacteria) can be recognised at rivers and streams as a dark 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, warm temperatures and low stable flows.

Environment Southland senior scientist Katie Blakemore said water users should be vigilant and avoid contact with the algae.

Katie said similar algae growth may be occurring in other places along the Waikaia River, its tributaries and other rivers in the region.

“These algae can produce toxins that are harmful to people and animals if swallowed, or through contact with skin. People should keep dogs on lead and children away from affected areas. 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.

In addition to weekly summer monitoring, Environment Southland monitors toxic algae monthly during the rest of the year at a number of river and lake sites across Southland.

Click here for further information www.es.govt.nz/toxic-algae

ENDS