A potentially toxic algae has reappeared on a lake near Dunedin.
The Otago Regional Council says it will be putting out signs again at Lake Waihola, south of the city, to warn about the dark green plant called anabaena which can produce toxins that kill animals and make people ill.
Blooms of the algae first formed at the lake and at Tomahawk Lagoon in Dunedin in early December, but cleared about three weeks ago.
Marion Poore, the Otago-Southland Medical Officer of Health, says people should not swim in Lake Waihola and other water users should be careful.
