Health warning removed for algal bloom at Te Wairewa / Lake Forsyth

Friday June 7, 2013

The Community and Public Health division of the Canterbury District Health Board has lifted its algal bloom health warning issued on April 16, 2013 at Te Wairewa/Lake Forsyth.
Recent water testing at Te Wairewa/Lake Forsyth has shown levels of potentially toxic blue-green algae (planktonic cyanobacteria) in the lake has decreased and concentrations are now below the levels that are of concern to public health.
Canterbury Medical Officer of Health Dr Ramon Pink says Environment Canterbury’s sampling of Lake Te Wairewa/Lake Forsyth will continue.
“The public will be informed if testing shows that concentrations have increased and there is a risk to public health again,” 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.
Or contact Community and Public Health on (03) 364 1777.

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Page last reviewed: 09 July 2013