Tuesday 5 February 2019Media release3 minutes to read
Canterbury District Health Board’s Community and Public Health unit have issued a health warning after potentially toxic blue-green algae (benthic cyanobacteria) were found in the Ashley/ Rakahuri River near the State Highway 1 Bridge.
There are also other access points along the Ashley/ Rakahuri River that may have cyanobacteria present and people are advised to check for the presence of cyanobacteria and avoid contact.
The cyanobacteria mats are detaching from the riverbed and becoming exposed as the water recedes and therefore people and animals, particularly dogs, should avoid the area of the Ashley/ Rakahuri River near the State Highway 1 Bridge until the health warning has been lifted.
Dr Alistair Humphrey, Canterbury Medical Officer of Health, says the algae look like dark brown to black mats and can produce toxins harmful to people and animals.
“Exposure may cause skin rashes, nausea, stomach cramps, tingling and numbness around the mouth and fingertips,” Dr Humphrey says.
“If you experience any of these symptoms, visit your doctor immediately, also let your doctor know if you’ve had contact with dark brown/black algal mats or water in this area.”
“No-one should drink the water from the river at any time, even after boiling the water from the river, it does not remove the toxin therefore should not be consumed,” Dr Humphrey says.
Pets should be taken to a vet immediately if they are showing signs of illness after coming into contact with algal mats.
People and animals should remain out of the waterways until the warnings have been lifted.
Environment Canterbury is monitoring the sites and the public will be advised of any changes in water quality.
Facts about cyanobacteria:
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Page last updated: 30 July 2020
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