Discovery of a potentially toxic blue-green algae bloom has sparked a health warning for the Selwyn/Waikirikiri River near Chamberlains Ford, south of Christchurch.
The Community and Public Health division of the Canterbury District Health Board has issued the warning following the discovery of a moderate cover of the algae, benthic cyanobacteria, in the river.
People and animals, particularly dogs, should avoid the area of the river near Chamberlains Ford until the health warning has been lifted.
Canterbury Medical Officer of Health Dr Ramon Pink 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 Pink said.
"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," he said.
Pets that show signs of illness after coming into contact with algal mats should be taken to a vet immediately.
Dr Pink says people and animals should remain out of the affected 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.
SHARE ME