April 26, 2017
Health warning lifted for Pegasus Lake
The Community and Public Health division of the Canterbury District Health Board has lifted its algal bloom health
warning issued at Pegasus Lake on 14 February 2017.
Recent water testing at Pegasus has shown the quantity of potentially toxic blue-green algae (planktonic cyanobacteria)
in the lake has decreased and concentrations are now below levels of concern to public health.
Dr Ramon Pink, Canterbury Medical Officer of Health, says as we move into winter there is a decreased chance of the
toxic algae returning until the warmer months.
“People are reminded to be aware of the signs of the presence of cyanobacteria in the lake, as the monitoring frequency
has now reduced from weekly to monthly,” Dr Pink 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.
• If a warning is in place, people and animals should not drink the water from the lake at any time, even boiled
water.
• Exposure to an algal bloom can 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 lake water when there is a health warning in place.
For further information visit https://www.ecan.govt.nz/your-region/your-environment/water/swimming-water-quality/ or contact Community and Public Health on (03) 364 1777.
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