High levels of toxic algae along Waikanae River, Kāpiti

Red alert level warnings for toxic algae are in place for the Waikanae River at the old State Highway 1 and Jim Cooke Park, Kāpiti. Toxic algae, or cyanobacteria, is harmful to humans and lethal for dogs if ingested. 

Greater Wellington senior advisor integration and insights Penny Fairbrother says detached algal mats are widespread at both sites, with the potential to harm pets who love playing in the water.  

“The warm autumn air and lack of rain has allowed toxic algae to regrow, forming mats at the river’s edge that can be very tempting to dogs. 

“Toxic algae is a neurotoxin that acts a bit like snake venom. Even the smallest amount – the size of a 50-cent coin – is enough to kill a dog.” 

Dog owners who think their animals have swallowed toxic algae, or shows signs of lethargy, muscle tremors, fast breathing, paralysis or convulsions, should go to the nearest vet immediately.    

People who have been in contact with toxic algae and are feeling unwell, should see a doctor or ring Healthline on 0800 611 116. 

“You can identify toxic algae by looking out for leathery dark green or black mats clinging to rocks, or clumps of brown at the river’s edge. The best antidote for toxic algae is to avoid it all together,” adds Fairbrother.  

Greater Wellington encourages everyone to check LAWA website warnings and alerts before visiting rivers in the Wellington Region.

Learn more out toxic algae. 

Check for toxic algae alerts at the LAWA website