Te Whatu Ora has issued a health warning after potentially toxic blue-green algae (planktonic cyanobacteria) was found in Saltwater Creek/ Ōtipua at both the SH1 bridge and the monitoring site at Saltwater Creek – rowing club. People should avoid the area and animals, particularly dogs, should not be allowed near the water until the health warning has been lifted.
Dr Matt Reid, Medical Officer of Health for Te Mana Ora, National Public Health Service, says the algae can appear as a thick surface scum, sheens or can be present as green globules floating in the water column and can produce toxins harmful to people and animals.
“People should avoid contact with the water until further notice.”
“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 and please let your doctor know if you have had contact with the river water”, Dr Reid says.
Pets that show signs of illness after coming into contact with potentially toxic algae should be taken to a vet immediately.
People and animals should remain out of the waterways until the warnings have been lifted.
Fish and shellfish can concentrate toxins and their consumption should be avoided. If fish are eaten, remove the gut and liver and wash in clean water.
Further information on gathering Mahinga Kai can be obtained below.
“People are advised to avoid contact with the downstream water bodies,” says Dr Reid.
Environment Canterbury is monitoring the sites and the public will be advised of any changes in water quality.
Facts about cyanobacteria
– Cyanobacteria occur naturally but can increase rapidly during warmer months.
– Algal blooms are caused by a combination of nutrients in the water (such as nitrogen and phosphorus), and favourable weather conditions (e.g., increased temperature, calm days).
– If the water is cloudy, discoloured, or has small globules suspended in it, avoid all contact.
– Not all cyanobacterial blooms are visible to the naked eye and toxins can persist after the blooms disappear.
– Cyanobacterial concentrations can change quickly with changing environmental conditions (e.g., wind). If a health warning is in place avoid contact with the water.