Duck hunters are warned to keep an eye on man's best friend as a toxic algae lingers on Lake Ellesmere.
The duck shooting season opened on Saturday, and Canterbury District Health Board has told hunters and their dogs to steer clear of Te Waihora/Lake Ellesmere and Lake Rotorua near Kaikoura as the blue-green algae continues to bloom.
Canterbury Medical Officer of Health Dr Ramon Pink said the lakes had concentrations of blue-green algae (planktonic cyanobacteria) above the levels considered safe for recreational activities.
"People should avoid contact with these lakes until the health warnings have been lifted."
Dr Pink said algae was particularly harmful to dogs, and hunters were recommended to not let their pets come into contact with or drink water from the lakes.
Shooters should also wash their hands thoroughly if they came in contact with the lake water or when handling ducks from the lake.
He said there was a high chance of respiratory, irritation and allergy symptoms from exposure to the high amounts of algae in the area.
"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.
"Ducks from the lake are fine to cook and eat if their gut has been removed," said Dr Pink.
Environment Canterbury was monitoring the lake and would notify the public when the concentration of algae had decreased to a safe level.
Facts about cyanobacteria:
The algae occurs naturally but can increase rapidly during warmer months
If the water is cloudy, discoloured, or has small globules suspended in it, avoid all contact
Not all cyanobacterial blooms are visible and toxins can persist after the blooms disappear
Cyanobacterial concentrations can change quickly with changing environmental conditions (eg wind). If a health warning is in place avoid contact with the water.
For further information visit http://ecan.govt.nz/services/ or contact Community and Public Health on (03) 364 1777