Toxic algae possibly widespread in Southland rivers

Environment Southland’s latest monitoring has found high levels of toxic algae at the Aparima River at Otautau.

There are already three other active toxic algae warnings in the region; the Waikaia River at Mahers Beach, the Hamilton Burn at Affleck Road and the Waiau River near Excelsior Creek.

This fourth alert highlights the need for people to be vigilant as the warm summer continues across the country.

Environment Southland senior scientist Roger Hodson said Environment Southland monitors for toxic algae weekly during summer. “We can’t assess every reach of every river, so it’s really important that people know what to look for and take a cautious approach to swimming and walking dogs off-lead along rivers.”

Toxic algae (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 a sudden increase in temperature, low flows, high levels of nutrients and run-off into waterways.

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 river and be mindful of the potential health risks, until health warnings are removed.

With the warmer weather, similar growth is likely occurring in other places across the region.

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.

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.

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

ENDS