Water warnings for Lake Ellesmere and Selwyn River
The Canterbury District Health Board is issuing a health warning after potentially toxic blue-green algae was found in the Selwyn River at the Whitecliffs Domain and in Lake Ellesmere .
The algae can produce toxins harmful to people and animals.
Canterbury medical officer of health, Dr Alistair Humphrey, said people should stay out of the water at both of these places until the health warnings have been lifted.
‘‘Contact with the algae may cause skin rashes, nausea, stomach cramps, tingling and numbness around the mouth and fingertips,’’ Dr Humphrey said.
‘‘People should not drink water from the Selwyn River at the Whitecliffs Domain or Lake Ellesmere at any time. Importantly, boiling water does not remove the toxins’’.
‘‘If you experience any of these symptoms visit your doctor immediately and let your doctor know if you have potentially had contact with the algae.
He said the algae was particularly dangerous for dogs.
‘‘Dogs should be kept away from both places until the health warning has been lifted. Animals that show signs of illness after coming into contact with the water should be taken to a vet immediately’’.
Environment Canterbury will monitor the site and the public will be advised of any changes in water quality.
The algal bloom is predominantly comprised of picocyanobacteria which have been found to produce toxins in studies around the world.
● It 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.