Blue-green algae Red Alert Downstream from Merbein on the Murray River to Fort Courage

Blue-green algae Red Alert Downstream from Merbein on the Murray River to Fort Courage

12 March 2020

A new red alert level warning (high alert) is in place for a 40 km section of the Murray River below Merbein and includes the locations of Wentworth and Fort Courage. The red alert issued for the Psyche Bend to Merbein section of the river remains current.

The declaration of a red alert follows field observations undertaken by WaterNSW personnel as dense surface scums are now evident. Increased water quality monitoring will be undertaken upstream and downstream from the red alert area. The public are advised that levels of blue green algae continue to fluctuate in the lower reach of the Murray River.

A red alert level warning indicates that people should not undertake recreational activities where they may be coming into direct contact with the water. Contact with the water may also pose a threat to livestock, and pets. The dominant cyanobacteria detected are known to be toxin producers and may produce a strong musty odour.

People are advised not to enter the water, not to drink untreated water or bathe in untreated water while a red alert level warning is in place. Boiling the water will not remove algal toxins.

People should not eat fish, mussels or crayfish from red alert warning areas.

Blue-green algae usually appear as green paint-like scums on the water, near the edges, or as greenish clumps throughout the water. It makes the water appear dirty, green or discoloured and generally has a strong musty or earthy odour

Blue-green algae occur naturally and can reproduce quickly in favourable conditions where there is still or slow-flowing water, abundant sunlight and sufficient levels of nutrients. It is not possible to predict how long the algae will remain at high levels. Regular monitoring will continue, and the alert will be lifted as soon as the high levels of algae dissipate.

People who believe they may have been affected by blue-green algae are advised to seek medical advice.

Updates about blue-green algae blooms and red level warning areas can be obtained by calling 1800 999 457 or visiting –

General inquires – Elizabeth Symes – 0439 077 199

Media Contact – Tony Webber – 0428 613 478


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