Toxic algae present in Queenstown waterways
Queenstown Lakes District Council and Otago Regional Council have confirmed that toxic algae is present in some waterways around Queenstown.
Phormidium has been detected in a creek at Hanley’s Farm and is unsafe to swim in and for dogs, who may be attracted to the musky smell.
The toxic algae is naturally occurring and plays an important role in the ecosystem, however it can produces toxins that are harmful to humans and animals. It grows suspended in the water, which causes dense mats to be formed across rocks – its growth increases in warmer temperatures to higher concentrations and forms ‘blooms’. The level of toxicity can only be known through lab testing, so it should always be treated as toxic.
Exposure can occur when spending time in water that contains blooms – contact with skin may cause a reaction and accidental ingestion could lead to more serious health issues. Coming into contact with the algae can make you or any animals feel unwell, and in extreme cases could result in death. Symptoms for humans include nausea and diarrhoea, and for dogs include lethargy, muscle tremors, fast breathing, twitching, paralysis and convulsions.
Despite the issues caused by the algae, it is a natural phenomenon that happens annually and there is not much that can be done about its occurrence. Otago Regional Council recommend the public remain especially vigilant during summer, and keep an eye on dogs around water.
“It’s happening all around the country and is mainly caused by the warm weather. It’s not something that is a concern for spreading from contamination, it just blooms at this time of the year because of the temperatures. The public should just be aware of it, look at the photos and know what it looks like so that you know, especially if you are walking dogs. We rely on our monitoring systems and the public to notify us, but it can be found in places that we’ve not been told about,” said a spokesperson for the Otago Regional Council.
It was a big weekend for Queenstown’s waterways, in addition to the algae at Hanley’s Farm, there were further reports of 10 dead ducks at Buckler Burn Stream near Glenorchy where water samples and the ducks have now been collected, and household wastewater was entering Horne Creek in town after a plumbing issue for a home on Hallenstein Street. The issue was caused by a faulty connection that mixed waste and stormwater. The homeowners have now contacted a plumber and Otago Regional Council have been taking water samples and will investigate the issue further.
If you notice any water issues or see any potential environmental contamination, it’s recommended that you report these to Otago Regional Council. The council are reliant on members of the public reporting any issues so that they can test and investigate further. You can make a report at the 24 hour pollution hotline on 0800 800 033 and you can stay up to date on areas of concern at orc.govt.nz/toxicalgae
