Health Warning Update Cyanobacteria Bloom – Eastern Bay of Plenty
Environment Bay of Plenty has carried out daily surveys of the waterways in the Eastern Bay of Plenty following the
recent discovery of toxic cyanobacteria on the Rangitaiki, Waimana, and Whakatane rivers.
Rangitaiki / Waimana Rivers
The Medical Officer of Health has extended the health warning advising against recreational use of the Rangitaiki River
from Murupara to the river mouth at Thornton following the identification of potentially toxic cyanobacteria in the
Galatea area. The health warning for the Waimana River from Te Urewera National Park to Taneatua remains in place.
Until further notice, people are advised not to paddle, wade, swim, or participate in any recreational activity that
might involve significant contact with the cyanobacteria mats or swallowing of raw river water. The health warning also
includes people keeping their pets (e.g. dogs) and livestock out of the river. Although initial testing has not yet
shown significant levels of free toxin in flowing water (i.e. toxin released by the mats), the use of untreated water
for drinking (people and animals) is not recommended (further tests are being conducted).
Small areas of cyanobacterial mats have been found in the Whakatane River and the public are advised to exercise caution
when using the river for recreational activity and to avoid direct contact with the dark brown/black or golden-brown
cyanobacteria mats that develop in shallow areas of the river, particularly along the riverbanks.
Whakatane District Council will place warning signs at places where people would usually have access to the rivers.
Anyone suffering illness after contact with the Rangitaiki and Waimana River should seek medical assistance. Any illness
in pets or livestock after contact with the river should be reported to the Medical Officer of Health.
The Whakatane District Council has consulted with the Medical Officer of Health and taken appropriate steps to manage
the minimal potential risk that relates to the town’s treated drinking water supply. The Council has increased
monitoring and introduced additional treatment as a precautionary measure.
Environment Bay of Plenty, Whakatane District Council, and Toi Te Ora – Public Health will be monitoring the situation
and have placed information on toxic cyanobacteria on their websites. Toi Te Ora - Public Health will update the public
when results from further tests are available.
Cyanobacterial mats vary from dark brown/black and are moss like in appearance, thickness and colour (black to dark
green) but have a much slimier texture and glisten when exposed to air. In shallow areas the mats may appear bleached
and take on a golden brown colour. The mats are easily dislodged from the riverbed and form floating ‘rafts’.