A vast swath of blue-green algae is making its way through Australia, creeping down Victoria’s Lower Murray Darling River at a pace that alarms authorities. At the end of March, the algae had already covered more than 300 kilometers from Hume Dam to the Torrumbarry Weir. Officials fear it could reach the border of South Australia within three to four weeks.
“We are seeing it slowly move downstream, but we want to make sure we’ve got monitoring in place that will keep us well and truly up to date as it’s progressing along,” said Owen Russell, general manager of Victoria’s Lower Murray Water Corporation.
Low water levels and high temperatures have combined to produce the perfect conditions for such an outbreak. Algal blooms are often caused by fertilizer-rich agricultural runoff. The blooms harm river ecology, causing eutrophication — which occurs when the algae creates a barrier, preventing sunlight and oxygen from reaching organisms within the water.
The government has issued a high level red alert, as the spread exceeds 400 kilometers. Tourism businesses worry that the possibly toxic algae will discourage Easter tourists and further drive down profits. After more than a decade of drought and increasingly damaging bushfires, revenues from tourism and agriculture in Victoria and South Australia continue to plummet.
“It’s still a lovely place to visit, there’s lots of other areas within the region and within our towns,” Barb MacDermid from Yarrawonga-Mulwala Tourism told Australia’s ABC.
“But of course that is always the big worry. We’ve just got over the other part of Victoria, the fires, we’re just trying to resurrect a lot of tourism within the regions.”