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Keep away from toxic algae in rivers

Phormidium fully exposed

With temperatures warming up, people using Hawke’s Bay’s stony rivers for swimming or walking dogs need to keep a look out for potentially toxic algae.

Summer is the year time of year when the chance of coming into to contact with potentially toxic algae or Phormidium in rivers is the highest says Regional Council Scientist for Water Quality and Ecology Dr Gary Rushworth.

“The main risk comes from humans touching it, or dogs eating it. If your child becomes ill after going to the river it’s best to take them to the doctor, and to take dogs to the vet,” says Dr Rushworth.

“Our advice is to always treat the black growth on rocks in water and the drying mats as toxic, and stay out of the water if you see it. We’ve developed a guide on our website to help you identify it,” says Dr Rushworth.

“Our monitoring has shown that the amount of algae in rivers can change quickly, so while our monitoring gives us an idea of what’s going on we are asking river users to be cautious and keep an eye out.”

The Regional Council is working to improve water quality in our rivers, such as high levels of nitrogen in some places.

Head to our swimming hub to see spots that are more likely to have Phormidium based on historical monitoring. There are advisory signs along the Tukituki River reminding people of the risks and showing them what to look out for.

20 November 2020

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