Scoop has an Ethical Paywall
License needed for work use Register

Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search


Toxic Algal Blooms Prompt Vigilance Call – ORC

The public are being asked to be vigilant in spotting potentially toxic algae blooms forming in some Otago waterways – with the ORC now reporting four areas of concern in recent weeks.

Yesterday, the latest sample collected on 18 December found toxic algae (cyanobacteria) present at Lake Waihola, south of Dunedin, and potentially toxic algae has also been observed at Waianakarua River, in North Otago, says ORC’s Scientist – Water Quality, Helen Trotter.

“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,” Ms Trotter says.

The public should continue to avoid contact with the water at Butchers Dam and connected waterbodies, and at Lake Waihola, until further notice, she says.

Algae was found in Butchers Dam earlier this month, and concerns over the death of three dogs near Alexandra last Friday also raised concerns around the lower Manuherekia, while upstream at Ophir there are already signs in place warning of a toxic algal bloom.

“If you or your pet are experiencing symptoms after contact with contaminated water, please visit a doctor or vet immediately,” Ms Trotter says.

The dog deaths near Alexandra have not yet been confirmed as linked to algae, but people are being asked to be prudent when excising pets around any waterways at present and avoid any algae.

Ms Trotter notes both wet and dried algae above the waterline can still be toxic.

Advertisement - scroll to continue reading

Are you getting our free newsletter?

Subscribe to Scoop’s 'The Catch Up' our free weekly newsletter sent to your inbox every Monday with stories from across our network.

Rivers which are known cyanobacteria hotspots around Otago are Silver Stream, Mosgiel, Cardrona River, Central Otago, Manuherekia River, Central Otago, Hāwea River, Central Otago, Waianakarua River, North Otago.

Lakes which are known cyanobacteria hotspots in Otago are Lake Waihola, Tomahawk Lagoon in Dunedin and Butchers Dam in Central Otago.

Ms Trotter encourages anyone who thinks they have seen toxic algae to take a photo, contact ORC as soon as possible on its Pollution Hotline; 0800 800 033. ORC staff are rostered on over the holiday period to respond to environmental incidents.

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

Benthic cynaobacteria (toxic algae) in rivers

“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.

If in any doubt, stay out,” Ms Trotter says.

Two web sites people should be familiar with are LAWA’s,

and to find the latest toxic algae sightings, go to: .

Ms Trotter says ORC follows the Ministry for the Environment guidelines in managing our response to potentially toxic algae.

“We will put up warning signs at popular access points when toxic algae reach levels that pose a risk to human and animal health,” she says.

Watch for symptoms, signs of poisoning.

Exposure to toxic algae may cause symptoms such as:

• Skin rashes

• Nausea

• Tummy upset

• Tingling and numbness around the mouth or tips of fingers.

Signs of poisoning in animals include:

• Lethargy

• Muscle tremors

• Fast breathing

• Twitching

• Paralysis

• Convulsion

Find the latest toxic algae updates and sightings:

© Scoop Media

Advertisement - scroll to continue reading
Parliament Headlines | Politics Headlines | Regional Headlines

Gordon Campbell: On National Spreading Panic About The Economy

It is a political strategy as old as time. Scare the public with tales of disaster and stampede them into supporting your ideological agenda because they believe There Is No Alternative. Yet, if the NZ economy truly is as “fragile” as PM Christopher Luxon says it is... Then how come New Zealand has enjoyed a double AA+ credit rating from the international rating agencies for so long? If we have truly been in the thrall of incompetent tax, spend and borrow extremists for the past six years, how come our net government debt burden is only in the middling average of OECD countries, and how come our government debt-to-GDP ratio – however you measure it – is less than half the average for the Asia-Pacific region?..


Labour: Grant Robertson To Retire From Parliament
Labour List MP and former Deputy Prime Minister and Minister of Finance Grant Robertson will retire from Parliament next month, and later in the year take up the position of Vice Chancellor of the University of Otago... More

Government: Budget Will Be Delivered On 30 May

Plans to deliver tax relief to hard-working New Zealanders, rebuild business confidence, and restore the Crown’s finances to order will be unveiled on 30 May, says Nicola Willis... More

Government: Humanitarian Support For Gaza & West Bank

Winston Peters has announced NZ is providing a further $5M to respond to the extreme humanitarian need in Gaza and the West Bank. “The impact of the Israel-Hamas conflict on civilians is absolutely appalling," he said... More

Government: New High Court Judge Appointed

Judith Collins has announced the appointment of Wellington Barrister Jason Scott McHerron as a High Court Judge. Justice McHerron graduated from the University of Otago with a BA in English Literature in 1994 and an LLB in 1996... More




InfoPages News Channels


Join Our Free Newsletter

Subscribe to Scoop’s 'The Catch Up' our free weekly newsletter sent to your inbox every Monday with stories from across our network.