Health authorities are urging the public to stay away from a Canterbury lake following the discovery of potentially toxic blue-green algae.
The Canterbury District Health Board has issued a health warning over Lake Forsyth/Te Wairewa - a small body of water between Christchurch and Akaroa.
Canterbury Medical Officer of Health Dr Alistair Humphrey says high concentrations of the cyanobacteria anabaena have been observed. The algal bloom forms green globules that float in the water and can be harmful to humans and animals.
"Exposure may cause skin rashes, nausea, stomach cramps, tingling and numbness around the mouth and fingertips," he says. "If you experience any of these symptoms visit your general practice team immediately and please let your doctor know if you have had contact with the lake water."
People should not drink or touch the water at any time. Boiling water does not remove the toxin, while fish and shellfish can also carry the bacteria.
Cyanobacteria can occur naturally and often spreads during summer. Nutrient overload, particularly nitrate and phosphorous, can heighten the risk.
The health warning could be in place for quite some time with Environment Canterbury to monitor the lake weekly and advise the public of any changes.
source: newshub archive