Lake Hume, New South Wales/Victoria

Location: Lake Hume, NSW/VIC (Wiradjuri Country)

Impact: Utility water

Focus: Algal blooms

Lake Hume, is a large reservoir of water in the Murray-Darling Basin held by a dam wall, which aims to regulate and conserve water for human consumption, tourism, recreation and the environment. Toxic algal blooms are becoming more frequent in the lake, often resulting in financial impacts that reach millions of dollars.

Currently, algal alerts are issued based on thresholds for cell counts or biomass. However, these methods are time-consuming and fail to deliver, real-time information.

Toxic blue-green algal blooms

Toxic blue-green algae, also known as cyanobacteria, are microscopic organisms found in freshwater and marine environments. These bacteria can produce harmful toxins called cyanotoxins, posing risks to the health of people, domestic animals and wildlife.

Under specific conditions like warm temperatures and excessive nutrient levels, toxic blue-green algae can rapidly multiply, forming dense blooms that give the water a green or blue-green appearance. Once released, some toxins may persist for more than three months before they degrade.

Taking precautions like avoiding direct contact with the water and reporting sightings can help minimize the impact of these harmful algal blooms and protect our communities and ecosystems.

Implications for water management

• Help identify chlorophyll levels in the water in near-real time, which may be an early indicator of an algal bloom.

• Integrate water-based measurements with satellite image data from Earth observation to provide a more holistic view of the whole lake.

• Use hydrodynamic, biogeochemical and algal growth models to help forecast potential algal blooms and provide early warning.