MEDIA RELEASE
DATE: 9 June 2011
SUBJECT: Health warning removed for algal bloom on the Ashley River

The Community and Public Health division of the Canterbury District Health Board has lifted its algal bloom health warning issued for the Ashley River. Warnings for this river were issued on 20 January 2011.

Recent surveys on the Ashley River have shown that the quantity of potentially toxic blue-green algae (benthic cyanobacteria) in the river has decreased to a level below that of concern to public health.

A number of rivers in Canterbury were issued with health warnings over the summer season. The surveys of these rivers, which are carried out by Environment Canterbury, have now ceased until next summer. Although there is a decreased likelihood of cyanobacteria growth over winter the public are still encouraged to remain vigilant and refrain from contact with the mats.

Facts about cyanobateria:
• 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 http://ecan.govtnz/services/online-services/monitoring/swimming-water-quality/Pages/river-warnings.aspx

ENDS

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