Lake Pegasus - potential toxic blue-green algae
February 14, 2017
The Community and Public Health division of Canterbury District Health Board has issued a health warning after
potentially toxic blue-green algae (planktonic cyanobacteria) were found in Lake Pegasus.
Dr Ramon Pink, Canterbury Medical Officer of Health says the algal bloom can produce toxins harmful to humans and
“People and animals, particularly dogs, should avoid contact with Lake Pegasus until the health warning has been
lifted,” Dr Pink says.
“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 them know you have had contact with the
No one should drink the water from the lake at any time, Dr Pink says. Boiling the water does not remove the toxin.
“This bloom will be monitored on a weekly basis and the public will be advised of any changes that are of public health
significance,” he says.
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.
Or contact Community and Public Health on (03) 364 1777.