Health warnings for the Waikaia River in northern Southland have been lifted, after monitoring results showed the presence of cyanobacteria has reduced to below surveillance levels.
Monitoring carried out by Environment Southland showed a high abundance of the naturally occurring and potentially toxic algae in mid January.
Public Health South issued a warning for people and animals to avoid contact with the river.
“Contact with cyanobacteria can affect people’s health so we’re pleased recent monitoring shows that the levels have dropped,” says Dr Marion Poore Medical Officer of Health.
This warning has now been withdrawn, with the high density of cyanobacteria mats moved as a result of recent high river flows.
Environment Southland surface water quality scientist Roger Hodson says cyanobacteria can occur naturally and increase rapidly during warmer periods.
“All Southlanders should be vigilant as cyanobacteria could be growing in other rivers that aren’t monitored on a regular basis. If anyone does come across it they should avoid contact with the cyanobacteria mats and water, and report their observations to Environment Southland. Photographs are an ideal way to do so,” he says.