Hunters reminded of toxic algae in Lakes Forsyth, Rotorua and Roundabout

Wednesday May 1, 2013

Hunters are reminded to avoid contact with three Canterbury lakes this duck shooting season because of toxic algae.
This year’s duck shooting season opens on Saturday, May 4.
The Community and Public Health division of Canterbury District Health Board is warning the toxic algal bloom notice, for Te Wairewa/Lake Forsyth on Banks Peninsula, Lake Rotorua near Kaikoura and Lake Roundabout near Ashburton, remains in place as duck shooting season approaches.
Dr Alistair Humphrey, Canterbury Medical Officer of Health, says the lakes are still in bloom with concentrations of blue-green algae (planktonic cyanobacteria) above the levels considered to be safe for recreational activities.
“People should avoid contact with these lakes until the health warnings have been lifted, because there is increased probability of respiratory, irritation and allergy symptoms from exposure to the high density of the cyanobacterial material present,” Dr Humphrey says.
“If you experience any of these symptoms visit your general practice team immediately and please let your doctor know if you have had contact with the lake water.”
Dr Humphrey says algae are particularly harmful to dogs and hunters should not let their pets come into contact with or drink water from the lakes.
“Hunters should also wash their hands thoroughly if they come in contact with the lake water or when handling ducks from these lakes. However, ducks can be cooked and eaten if their gut has been removed.”
Environment Canterbury continues to monitor the lakes and the public will be advised when they are clear of concentrations of algae deemed to be of public health significance.
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 and toxins can persist after the blooms disappear.
  • Cyanobacterial concentrations can change quickly with changing environmental conditions such as wind.
  • If a health warning is in place avoid contact with the water.
Or contact Community and Public Health on (03) 364 1777.
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Page last reviewed: 09 July 2013