Hunter Local Land Services said with several red alerts issued in the Hunter region, landholders should be on the lookout for blue green algae.

HLLS said 12 cattle died recently in the Murray region from blue green algae toxicity after drinking water from an isolated farm dam.

Blue green algae may produce toxins that can affect the nervous system or the liver of livestock, resulting in serious disease and potential death.

While blue green algae blooms are relatively common, livestock poisonings are not.

Currently there are red alerts at a number of locations, including:

•Hunter River Upstream of Glenbawn Dam

•Lostock Dam dam wall

•Lake Liddell recreational area WEST

•Lake Liddell Centre

•Lake Liddell CW Inlet

•Walka Water Works Dam

•Telarah Lagoon

•Rathluba Lagoon

Red alert levels represent ‘bloom’ conditions. The water may appear green and may have strong, musty or organically polluted odours. Blue-green algae may be visible as clumps or as scums. The ‘blooms’ should be considered to be toxic to humans and animals, and the water should not be used for drinking (without prior treatment), stock watering, or for recreation.

District Vet Jim Kerr said the warnings come as water supplies across the region become critical in many places, as ongoing hot dry weather continues to add to the impacts of the drought.

“Some rivers and creeks are again drying up, and it’s not just the quantity of water, the quality is obviously critical too with issues like blue green algae creating problems for livestock.

“Please remember that in these conditions, just one lactating cow can drink up to 100 litres of water a day, so it’s crucial producers ensure they have enough water on hand," Jim said.

More information about algae alerts and regular updates on local conditions can be found at https://www.waternsw.com.au/water-quality/algae

Landholders with concerns about livestock health and blue green algae in isolated farm dams should contact their nearest Local Land Services District Vet on 1300 795 299.