August 13, 2012
Health warning removed for algal bloom at Te Waihora/ Lake Ellesmere
The Community and Public Health division of the Canterbury District Health Board has lifted the health warning issued in January for Te Waihora/ Lake Ellesmere.
Recent water testing at Te Waihora/Lake Ellesmere has shown the quantity of potentially toxic blue-green algae (planktonic cyanobacteria) in the lake has decreased and concentrations are now below harmful levels to public health.
Dr Alistair Humphrey, Canterbury Medical Officer of Health, says Environment Canterbury’s sampling of Te Waihora/ Lake Ellesmere will continue on a monthly basis.
“Sampling frequency will step up if quantities of cyanobacteria increase above guideline levels. The public will be informed if testing shows that concentrations have increased and there is a risk to public health again,” Dr Humphrey says.
Facts about cyanobacteria:
algae occur naturally but can increase rapidly during warmer
• 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 http://ecan.govt.nz/services/online-services/monitoring/swimming-water-quality/Pages/lake-warnings.aspx or contact Community and Public Health on (03) 364 1777.