A red alert warning for blue-green algae now covers a 300-kilometre stretch of the Murray River, but the outbreak is still not as big as the last major bloom.
Following testing by authorities, the toxic alert has gradually expanded over the past week to cover waterways from Corawa to Torrumbarry Weir, including the Mulwala Main Canal offtake, Lake Mulwala, Moama and Echuca, as well as the Edward River from Picnic Point to Old Morago.
“Like nearly all Australian rivers, parts of the Murray are subject to blue-green algae blooms from time-to-time under the right conditions,” said Murray Regional Algal Coordinating Committee Acting Chair Chester Merrick.
“The extent of the current alert for the Murray River is presently smaller than the last major outbreak in 2010.”
Merrick added that drinking water supplies were not compromised.
“Appropriate water treatment is in place by the respective local water utilities and town water supplies remain unaffected and safe to drink,” Merrick said.
Irrigators are advised that using the water on fruit or vegetables could contaminate the produce, while people and animals should not enter the water.
“Livestock owners are advised to check stock water supplies for blue-green algae and to remove stock from foreshores where surface scum is visible or blue-green algae are suspected and provide alternative water sources,” Merrick said.
The department was posting warning signs at key recreational areas but said that due to the expanse of the bloom it was unable to erect warning signs at every public access point.
Merrick said it was not possible to predict how long the algae will remain at high levels.
“Regular monitoring will continue at numerous sites along the Murray River and the alert will be lifted as soon as the high levels of algae dissipate,” he said.
Related podcast:
https://omny.fm/shows/australianwater/tim-malthus-on-algal-bloom-early-warning-systems