The Community and Public Health division of the Canterbury District Health Board has lifted its algal bloom health warning issued along the Selwyn/Waikirikiri River at Glentunnel. This was issued on 21 December 2017.
Recent cyanobacteria monitoring of the water at the Selwyn/Waikirikiri River at Glentunnel has shown the coverage of potentially toxic blue-green algae (benthic cyanobacteria) in the river has decreased and is now below the levels that are of concern to public health.
Canterbury Medical Officer of Health Dr Alistair Humphrey says “Environment Canterbury’s monitoring season has finished and will not resume until November 2019, therefore the public is advised to check rivers they use for signs of cyanobacteria prior to entering them.”
“Lake Pegasus, Lake Forsyth/Te Roto o Wairewa and Lake Ellesmere/Te Waihora, which are still in bloom, will continue to be monitored on a monthly basis once warnings on these lakes are lifted.”
Facts about cyanobacteria:
• Appears as dark
brown/black mats attached to rocks along the
• 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.
For more information on Mahinga kai: