Blue-green algae (BGA) blooms have been reported with increasing regularity in inland river networks in Victoria, New South Wales and South Australia.
Sunraysia recently experienced a BGA outbreak, which triggered a Red Alert, extending from Red Cliffs to Lock 10 (issued 3 December 2019 for Mildura Weir Pool, later extended, and lifted 4 January 2020). When a Red Alert is issued, all channels and pipelines in the Red Alert Area are affected. Stored water is advised to remain isolated.
What are Blue-green algae?
Blue-green algae (cyanobacteria) are photosynthetic organisms that occur naturally in aquatic environments. Under favourable conditions, generally in warmer months, populations can increase rapidly causing a bloom.
Some species of BGA produce toxins which are harmful to humans, stock, domestic animals, and fish.
How does Blue-green algae affect irrigators?
BGA-affected water can cause blockages in irrigation systems reducing system efficiency and may cause produce to become contaminated with toxins—this is mainly an issue for irrigators using overhead sprays, which cause contaminated water to come in direct contact with edible parts of the crop.
It is not well understood whether toxins are taken up by plants when irrigated with contaminated water. Some investigations suggest toxins can up absorbed, but risks vary depending on environmental conditions, crop type and the quantity of the product consumed.
Further information can be accessed from NSW DPI here.
Lower Murray Water monitor and report on BGA in Sunraysia. Customers can register to receive SMS update alerts by contacting Lower Murray Water.
Content sources and further information
- Irrigating with blue-green algae affected water – NSW DPI Primefact
- Blue-green algae and irrigation water – Agriculture Victoria
- Blue green algae: What to look for
- Blue-green algae
- Blue-green algae in NSW