Tests carried out by Horizons Regional Council have shown very high levels of potentially toxic blue-green algae (cyanobacteria) at Lake Wiritoa, near Whanganui and Lake Dudding in Rangitikei.
Health warnings will be placed at the lakes. People are advised not to use the water for recreational purposes until these warnings are removed.
Cyanobacteria (also known as blue-green algae) may produce toxins that are harmful to humans and animals if swallowed or through contact with skin, such as may occur when swimming, water skiing or kayaking.
Exposure to cyanobacterial toxins may cause symptoms such as skin rashes, nausea, tummy upset and tingling and numbness around the mouth or finger tips.
If you experience health symptoms after contact with contaminated water, visit a doctor immediately. Boiling water does not remove toxins and drinking the water should be avoided at all times. Fish and shellfish can concentrate toxins and their consumption should be avoided.
Cyanobacteria occur naturally but can increase rapidly during summer, known as a “bloom”. If the water is cloudy, discoloured, or has small globules suspended in it, avoid all contact.
Horizons Regional Council monitors cyanobacteria in our recreational lakes during summer and the public will be advised of any changes in water quality that could be associated with health problems.
Not all cyanobacterial blooms are visible and toxins can persist after the bloom has disappeared. Cyanobacterial concentrations can change quickly with changing environmental conditions (e.g. wind). If a health warning is in place, avoid contact with the water.
Public Health Centre, MidCentral Health, Whanganui Hospital, on 06 348 1775 or Public Health Services, MidCentral Health, on (06) 350 9110.