North Canterbury residents have been warned to avoid a lagoon after a potentially toxic algae was found.
The blue-green algae has been found in St Annes/Mata Kopae Lagoon, a wildlife sanctuary near Cheviot.
Canterbury medical officer of health Dr Ramon Pink said people and their pets should avoid contact with the water until the warning is lifted.
"The algal bloom can produce toxins harmful to humans and animals. Dogs are particularly susceptible to the health risks."
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 lake water," Pink said.
The lake water should not be drunk, even if it has been boiled, nor should any fish or shellfish be consumed from the lagoon.
"If fish are eaten, remove the gut and liver and wash in clean water," Pink said.
"Animals that show signs of illness after coming into contact with the water should be taken to a vet immediately."
Environment Canterbury will monitor the lagoon weekly.
FACTS ABOUT CYANOBACTERIA
- The algae occur naturally but can increase rapidly during warmer months.
- 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.
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