A health warning has been issued for a North Canterbury lagoon after a toxic blue-green algae was found.
Canterbury's Medical Officer of Health Ramon Pink says people and animals should avoid the St Annes/Mata Kopae Lagoon, a wildlife sanctuary near Cheviot.
Dr Pink says exposure can cause skin rashes, nausea, stomach cramps, tingling and numbness around the mouth and fingers.
The algae gives the water a green soupy appearance and people or animals who show signs of illness after coming into contact with the water should visit a doctor or vet immediately, he says.
Even boiled water from this lagoon should be avoided, along with fish and shellfish.