Toxic Algae Alert for the Oreti River at the Winton Bridge

Environment Southland’s latest monitoring has found high levels of potentially toxic algae in the Oreti River at the Winton Bridge.

This alert is in addition to warnings already in place for the Waiau River at Tuatapere, Mataura River at Gore and the Ōreti River at Branxholme.

Water users should be vigilant and avoid contact with water and the algae, and swimming in the Oreti River at the Winton Bridge should be avoided.
Related: Toxic Algae Alert for the Ōreti River at the Winton Bridge

Similar growth may be occurring in other rivers and tributaries, so waterway users are advised to also be vigilant across Southland.

Algae occur naturally in waterways and can flourish during fine conditions and periods of stable river flows. Most algae are harmless, however, some cyanobacteria can produce toxins and rapidly bloom to high levels.

These algae are potentially toxic and can be commonly identified in waterways as a dark green/brown slime on rocks, or dark brown/black mats at the water’s edge.

The toxins these algae can produce are harmful to people and animals if swallowed, or through contact with skin.

People should keep dogs on a lead and children away from affected waterways.

The public is urged to be mindful of the potential health risks waterways with toxic algae alerts may pose, 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.

The use of hand sanitiser may not remove all the toxin from the skin, so clean, running water is best for washing hands and skin.

Environment Southland monitors toxic algae monthly at a number of rivers and lakes across Southland.