Source: Waikato District Health Board
CYANOBACTERIAL WARNING UPDATE: Health warning issued for Lake Rotokauri and Lake Rotoroa (Hamilton Lake) and remains in place for Lakes Ngā Roto, Hakanoa, Waikare and Kainui.
A new health warning has been issued today for Lakes Rotokauri and Rotoroa (Hamilton Lake) due to a rise in cyanobacteria biovolume to 1.85 mm3/L at Lake Rotokauri and 3.6 mm3/L at Lake Rotoroa (Hamilton Lake). Biovolume is the measure used to decide when a health warning should be issued, with the cut-off value for a health warning set at 1.8mm3/L.
Lakes Ngā Roto, Hakanoa, Waikare and Kainui continue to have a cyanobacterial health warning in place.
Waikato Regional Council monitors cyanobacteria levels at Lakes Kainui, Rotokauri, Ngā Roto, Puketirini, Waikare, Whangape, Hakanoa and Waahi.
Dr Richard Wall, Te Whatu Ora Medical Officer of Health for Waikato recommends that where cyanobacteria health warnings are in place, lakes should not be used for any activity that involves skin contact with the affected water.
“Swallowing water from lakes affected by blooms should also be avoided,” said Dr Wall.
“If people still choose to use the lakes when warnings are in place, or any other lake where there are visible changes to water colour, they should shower and change their clothing as soon as possible afterwards, even if no symptoms are noticeable,” he said.
Cyanobacteria can release toxins which can trigger asthma and hayfever symptoms, and can cause skin rashes, stomach upsets, and in some cases neurological effects such as tingling around the mouth, headaches, breathing difficulties and visual problems.
These symptoms may not appear until some time after contact with the affected water.
Scums are a particular risk because they contain a high level of toxins. If contact with scum does occur, skin should be rinsed clean and clothing changed as soon as possible. This warning is particularly important for children.
Dog owners should prevent their dogs from drinking or swimming in the water, as dogs are particularly sensitive to cyanobacteria.
Te Whatu Ora Public Health Unit for Waikato would like to be informed about health problems that develop after exposure to any of the Waikato lakes. Phone Waikato Public Health Service: 07 838 2569.
Up-to-date information on cyanobacterial health warnings is available by visiting the Land Air Water Aotearoa (LAWA) website at https://www.lawa.org.nz/explore-data/waikato-region/
