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 2 November 2018

Very low levels of non-toxic cyanobacteria were detected in a recent water sample collected from the lake outflow on Tuesday 30 October 2018. 

Those taking water downstream of the lake should still exercise some caution and NRC advises the water should not be used for human consumption.  The situation will continue to be monitored and further updates will be provided 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.