During the swimming season (Nov–Mar), Environment Canterbury assesses the health risks from faecal contamination (E.coli) and toxic cyanobacteria at popular freshwater swimming sites around the region.
Monitoring of E. coli
Monitoring of the ‘faecal indicator bacteria’ Escherichia coli (E. coli) is vital. ‘Indicator bacteria’ signal the levels of disease-causing organisms present in the water. It’s important to test for these in water used for recreational activities as they can pose a health risk. The most common illness they cause is gastroenteritis, but respiratory illness and ear/skin infections may also occur.
What is Cyanobacteria?
Cyanobacteria play an important roll in aquatic ecosystems, but become a problem when they produce toxins which can cause nausea and diarrhoea, and (in extreme cases) more serious health issues for both people and animals.
Routine monitoring for potentially toxic planktonic cyanobacteria is carried out monthly for Te Roto o Wairewa/Lake Forsyth and Te Waihora/Lake Ellesmere. This increases in frequency when potentially toxic planktonic cyanobacteria are identified.
The below health warnings are for planktonic cyanobacteria and faecal contamination (E.coli).