Warning about toxic algae in Tukituki
Warning about toxic algae in Tukituki
Water quality monitoring by Hawke’s Bay Regional Council staff indicates that potentially toxic algae levels are present on the Tukituki River, at Black Bridge near Haumoana.
Parts of the Tukituki River are prone to algal growth in summer, due to lower water flows, higher water temperatures and nutrients in the water. Green strand algae is harmless but black Phormidium bacteria growth on the rocks is potentially toxic for humans and dogs. It can detach from the rocks and dry as mats on the sides of the rivers, and these can also be toxic.
“Our advice is to always treat the black growth on rocks in the water and the drying mats as toxic, stay out of the water if you see it, and swim or walk your dog elsewhere,” says HBRC’s Senior Environmental Scientist Anna Madarasz-Smith.
She adds that science
has not yet identified when Phormidium turns toxic or why,
so to be safe it should always be treated as harmful.
•
Contact with Phormidium bacteria can make people sick, with
flu-like symptoms.
• Dogs are more vulnerable.
They are particularly attracted to the odour of the mats and
being smaller, the toxins can be more dangerous. Dogs
should be under control in river beds and not allowed to
scavenge. Clinical signs are vomiting, diarrhoea and
lethargy, and heat stroke- like symptoms such as muscle
tremors, breathing difficulties, paralysis and
convulsions.
People can check water quality and algae
warnings here which displays data from LAWA (Land
Air Water Aotearoa = www.lawa.org.nz).
Warning signs would be put up at affected areas by HB District Health Board staff, but people were urged to avoid contact with the cyanobacteria mats and to keep animals away.
For
information:
https://www.lawa.org.nz/explore-data/hawkes-bay-region/river-quality/tukituki-river/tukituki-river-at-black-bridge-(haumoana)/
What are Cyanobacteria?
Cyanobacteria are single
celled creatures that live in water environments.
Cyanobacteria have characteristics in common with both
bacteria and algae. In warm nutrient rich conditions
free-floating cyanobacteria cells can multiply quickly to
form what are known as algal blooms. Large numbers of
Cyanobacteria can also grow as mats on river and lake beds
and these mats can sometimes detach and float to the
surface. Some cyanobacteria species produce toxins
(cyanotoxins), which pose a risk to humans and animals when
consumed in drinking water or by direct contact during
recreational activities.