Greater Wellington advises people to avoid contact with the water at Lake Wairarapa Moana, where red alert level warnings are in place, due to a high concentration of cyanobacteria (toxic algae) found in the lake.

In lakes, toxic algae grow in a free-floating (also called planktonic) form which can cause the water to become murky or cloudy or give it a bright green ‘pea soup’ appearance.

Greater Wellington’s senior advisor for Integration and Insights, Penny Fairbrother says people should also look out for bright green scum which collects at the water’s edge.

“We’re advising that people avoid contact with the water and dogs should be on a leash and kept away from the water. Do not let them drink lake water or fetch sticks found near the water,” says Fairbrother.

“These high concentration levels have the potential to cause illness for both people and animals if the water is swallowed or breathed in, or if there is direct contact with the skin. The risk is highest for children, pregnant people and the elderly.”

“Other safety measures should be taken, including not collecting or eating shellfish from the lake. Fish caught from the lake should be gutted and cleaned properly and the guts safely disposed of so animals cannot scavenge them.”

If exposed to the algae, people are advised to call Healthline (0800 611 116), especially if experiencing symptoms such as nausea, skin irritation, breathing difficulties or numbness around the mouth and/or fingertips.

Dogs showing signs of lethargy, excessive panting, tremors or seizures should be taken to the vet immediately.

Greater Wellington will continue weekly sampling and testing at the lake while levels remain high.

To learn more about toxic algae in lakes, visit: LAWA - Algae and Cyanobacteria in Lakes

To check for toxic algae alerts in rivers in the Wellington region, visit: Land, Air, Water Aotearoa

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