Selwyn River health warning lifted
The Community and Public Health division of the Canterbury District Health Board has lifted its algal bloom health
warnings issued along the Selwyn River.
These were issued for Glentunnel in February and the Whitecliffs Domain in January.
Dr Ramon Pink, Canterbury Medical Officer of Health says recent surveys along the Selwyn River have shown that the
quantity of potentially toxic blue-green algae (benthic cyanobacteria) in the river has decreased to below levels that
are of concern to public health.
“Environment Canterbury’s sampling will resume next summer when there is increased likelihood of cyanobacteria growth,”
Dr Pink says.
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. It is important to treat every low-flowing river cautiously, especially keeping dogs away as the algae can be
particularly harmful to them.
For further information visit http://ecan.govt.nz/services/online-services/monitoring/swimming-water-quality/Pages/river-warnings.aspx
Or contact Community and Public Health on (03) 364 1777.
ends