Cyanobacteria (blue-green algae)

Cyanobacteria (commonly known as blue-green algae) are photosynthetic prokaryotic organisms that are integral parts of many terrestrial and aquatic ecosystems. In aquatic environments under favourable conditions, cyanobacterial cells can multiply and form planktonic (suspended in the water column) blooms or dense benthic (attached to the substrate) mats.

An increasing number of cyanobacterial species are known to include toxin-producing strains. These natural toxins, known as cyanotoxins, are a threat to humans and animals when consumed in drinking water or coming into contact with the skin during recreational activities.

Algal activity occurring in Northland

Waingaro Reservoir, Far North District – Update 23 November 2018

Cyanobacteria scums are still visible on the surface of the lake so lake water testing is continuing . Water is currently being taken from the lower depths of the lake where testing shows very low levels of non-toxic cyanobacteria present.

Those taking water downstream of the lake should still exercise some caution and NRC is still advising that the water should not be used for human consumption. The situation continues to be monitored and any updates will be posted on this page.

Frequently asked questions

Download our Cyanobacteria - FAQs document (PDF, 343KB) 

Report it

If you suspect a waterbody is experiencing a cyanobacterial bloom and there are no signs placed near the waterbody informing there is one – please contact the NRC 24hr Environmental Hotline to report it : 0800 504 639.