Health Warning – Algal Bloom in Te Waihora/Lake Ellesmere

Wednesday January 11, 2012

The Community and Public Health division of Canterbury District Health Board has issued a health warning because of increased concentrations of toxic algae (planktonic cyanobacteria) found in Te Waihora/Lake Ellesmere.
People and animals should avoid contact with the lake until the health warnings have been lifted. Canterbury Medical Officer of Health Dr Daniel Williams says the algal bloom contains the toxic Nodularia and therefore there is the increased risk of respiratory, irritation and allergy symptoms from exposure to the cyanobacterial material present.
“If you experience any of these symptoms visit your doctor immediately and please let your doctor know if you have had contact with the lake water,” Dr Williams says.
“No one should drink the water from the lake at any time. Boiling the water does not remove the toxin. Algae are particularly dangerous for dogs, so they should be kept away from the water.” 
Animals should be taken to a vet immediately if they display any unusual symptoms after coming into contact with the algal bloom.
“Eating fish should be avoided because the toxins can concentrate in their bodies. If fish are eaten, remove the gut and liver and wash in clean water,” Dr Williams says.
Environment Canterbury monitors the lake weekly during summer and the public will be advised of any changes in water quality that are of public health significance.
A warning remains in place for Te Wairewa/Lake Forsyth.
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.

Page last reviewed: 23 July 2013