A health warning has been issued for the Hurunui River at State Highway One after a moderate to high cover of potentially toxic algae was found.
The Canterbury DHB’s Community and Public Health unit says the algae (benthic cyanobacteria), may also be at other access points along the river.
People should avoid the area and animals, particularly dogs, should not be allowed near the water until the health warning has been lifted.
People are also advised to treat every low-flowing river cautiously, check for the presence of benthic cyanobacteria and avoid contact.
Canterbury Medical Officer of Health, Dr Cheryl Brunton says the algae looks 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.
“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,” Dr Brunton says.
Pets that show signs of illness after coming into contact with algal mats should be taken to a vet immediately.
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.