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Blue-green algal bloom health warning issued for Lake Whangape

The Waikato District Health Board (DHB) has issued a new health warning for Lake Whangape in the Waikato district due to raised levels of cyanobacterial toxins from algal blooms. 

A similar health warning remains in place for Waikato district’s Lake Waikare. 

Waikato DHB recommends that lakes affected by algal blooms should not be used for activity that involves skin contact with the water, and swallowing the water should also be avoided. 

Cyanobacteria are a form of algae which can produce toxins harmful to human and animal health. 

A news release issued by the Waikato DHB warns that if people use the affected lakes they should shower and change their clothing as soon as possible afterwards, even if no symptoms are noticeable. Symptoms include rash, skin and eye irritation; allergy symptoms such as hayfever and asthma; and possibly stomach upsets including diarrhoea and vomiting. 

Waikato Regional Council testing show cyanobacteria levels in Lake Whangape are 2.3 mm3/L (compared with a safe level of less than 1.8mm3/L) and in Lake Waikare they are 25.8mm3/L. 

Lake Ngaroto in the Waipa district is also subject to a health warning with a cyanobacterial level of 10.9mm3/L. 

Lakes Hakanoa and Waahi, the other Waikato district lakes tested regularly by Waikato Regional Council, currently remain below the warning level for cyanobacteria. 

Testing is conducted monthly during the warmer months, and two monthly over the winter. 

For more information see the full news release at