Canterbury DHB’s Community and Public Health unit has lifted its algal bloom health warning issued for Te Waihora/Lake
Recent water testing at Te Waihora/Lake Ellesmere has shown the quantity of potentially toxic blue-green algae
(planktonic cyanobacteria) in the lake has reduced and concentrations are now below levels that are of concern to public
Canterbury Medical Officer of Health Dr Cheryl Brunton says Environment Canterbury’s sampling of Te Waihora/Lake
Ellesmere will continue on a monthly basis.
“The public will be informed if testing shows that concentrations have increased and there is a risk to public health
again,” Dr Brunton says.Facts about cyanobacteria:The algae occur naturally but can increase rapidly during warmer months.Algal blooms are caused by a combination of nutrients in the water (such as nitrogen and phosphorus), and favourable
weather conditions (e.g. increased temperature, calm days).If the water is cloudy, discoloured, or has small globules suspended in it, avoid all contact.Not all cyanobacterial blooms are visible to the naked eye and toxins can persist after the blooms disappear.Cyanobacterial concentrations can change quickly with changing environmental conditions (e.g. wind). If a health warning
is in place avoid contact with the water.If a warning is in place, people and animals should not drink the water from the lake at any time, even boiled water.Exposure to an algal bloom can cause skin rashes, nausea, stomach cramps, tingling and numbness around the mouth and
fingertips. If you experience any of these symptoms visit your doctor immediately and please let your doctor know if you
have had contact with lake water when there is a health warning in place.
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Canterbury District Health Board
Canterbury District Health Board (CDHB) is a Christchurch, New Zealand based hospital and healthcare provider for the
Canterbury region of New Zealand. Our region extends from Kekerengu in the North, to Rangitata in the South and Arthurs
Pass in the West and comprises the six Territorial Local Authorities of Kaikoura, Hurunui, Waimakariri, Christchurch
City, Selwyn and Ashburton.
We collaborate with other health and disability organisations, stakeholders and our community to decide what health and
disability services are needed and how to best use the funding we receive from Government to improve, promote and
protect the health, wellbeing and independence of our population.
At the Canterbury DHB, our vision is to improve the health and wellbeing of people living in Canterbury.