Toxic algae found in the lower Mataura river

21 November 2017

Monitoring carried out by Environment Southland has detected potentially toxic algae in shallow areas/edges of the lower Mataura river.

The algae produces toxins that can be harmful to people and animals if swallowed, or through contact with skin.

Environment Southland’s freshwater & marine science leader Nick Ward says its important people know what to look for and take caution:

“The public need to keep a close eye out for this algae, which appears as a green/brown slime on rocks, or dry brown or black mats at the river’s edge. People and animals (in particular, dogs), should avoid contact with the slime, slime mats, and water in the area, and be mindful until health warnings are removed. Dogs should be kept on leads while walking near the Mataura, and children kept away from its water and riverbanks.”

If you experience health symptoms after contact with contaminated water, visit a doctor immediately. Animals that consume cyanobacteria should be taken to a vet immediately.

Toxic algae occur naturally but can increase rapidly during warmer periods of the year. The long-term forecast for 2017/2018 is for a long, hot summer, meaning a high likelihood of more toxic algae blooms in Southland waters.

Environment Southland monitors toxic algae monthly at a number of river and lake sites across Southland, and the public will be advised of any changes in water quality that are of public health significance.

Find out more about cyanobacteria and our monitoring programme

Read our Q&A to find answers to some of the frequently asked questions

Example of a cyanobacteria mat.

Page reviewed: 04 May 2016 11:53am