Potentially toxic algal bloom in Selwyn/Waikirikiri River
16 March 2018
Health Warning – Potentially toxic algal bloom in the Selwyn/Waikirikiri River at Chamberlains Ford
The Community and Public Health division of the Canterbury District Health Board have issued a health warning for the Selwyn/Waikirikiri River near Chamberlains Ford.
The warning follows finding a moderate cover of potentially toxic blue-green algae (benthic cyanobacteria) in the Selwyn/Waikirikiri River.
People and animals, particularly dogs, should avoid the area of the Selwyn/Waikirikiri near Chamberlains Ford until the health warning has been lifted.
Dr Ramon Pink, Canterbury Medical Officer of Health, says the algae look like dark brown to black mats and can produce toxins harmful to people and animals.
“Exposure may cause skin rashes, nausea, stomach cramps, tingling and numbness around the mouth and fingertips,” Dr Pink says.
“If you experience any of these symptoms, visit your doctor immediately, also let your doctor know if you’ve had contact with dark brown/black algal mats or water in this area.”
Pets that show signs of illness after coming into contact with algal mats should be taken to a vet immediately.
Dr Pink says people and animals should
remain out of the affected waterways until the warnings have
been lifted.
Environment Canterbury is monitoring the
sites and the public will be advised of any changes in water
quality.
Facts about cyanobacteria:
Appears as
dark brown/black mats attached to rocks along the
riverbed.
The algae occur naturally but can increase
rapidly during warmer months.
It often has a strong musty
smell and algal toxin concentrations can vary over short
periods with changing environmental conditions.
Although
high river levels will remove the algal bloom, detached mats
can accumulate along the shore and increase the risk of
exposure to toxins.
If a health warning is in place avoid
contact with the water.
Although district or city
councils may place warning signs, these may not be seen at
the numerous river access points, hence the need for people/
dog-walkers to treat every low-flowing river cautiously.
For further information visit https://www.ecan.govt.nz/your-region/your-environment/water/swimming-water-quality/
or contact Community and Public Health on (03) 364 1777.
https://www.cph.co.nz/your-health/recreational-water/
ENDS