The public are being asked to be vigilant in looking out for potentially toxic algae blooms after a number of areas of concern were reported to Otago Regional Council (ORC) in recent weeks.

Toxic algae (cyanobacteria) hotspots in Otago include the Cardrona and Hāwea rivers and people should be particularly vigilant if they visit the rivers with pets.

“We’re asking the public and people with pets to take extra care when visiting rivers and lakes at present, as the warm conditions are becoming ideal for toxic algae to bloom, ORC water quality scientist Helen Trotter said.

“Blooms are more common during the summer months, when low rainfall, warm temperatures, the right level of nutrients and more sunlight create an environment where it can thrive.

“However, in the right conditions toxic algae can bloom rapidly and just a teaspoon is enough to cause serious illness, or death, so people are urged to remain vigilant around our waterways this summer.”

Toxic algae or potentially toxic algae has recently been discovered at Lake Waihola, the Waianakarua River, Ophir and Butchers Dam.

The death of a Hāwea dog, and three dogs near Alexandra recently have not been confirmed as linked to algae, but people are being asked to be prudent when exercising pets around any waterways at present and avoid any algae.

Algae above the waterline - wet or dried - can still be toxic.

Exposure to toxic algae may cause symptoms such as skin rashes, nausea, tummy upset and tingling and numbness around the mouth or tips of fingers.

Signs of poisoning in animals include lethargy, muscle tremors, fast breathing, twitching, paralysis and convulsion.

Helen encouraged anyone who thinks they have seen toxic algae to take a photo and contact the ORC as soon as possible on its pollution hotline (0800 800 033.) 

“Prompt sightings by the public mean we can investigate and get signage up at access points as soon as possible,” she said.

People can keep up to date with the latest toxic algae sightings here.

 PHOTO: ORC