Whitehorse City Council

Blue Green Algae

Blue green algal blooms are bacteria that rely on sunlight for energy.

These cyanobacteria can be found in lakes, rivers, creeks and wetlands but normally in such small numbers that they are not visible.

As conditions change in the waterway and become favourable for the bacterium the numbers increase rapidly and blooms become visible on the surface. Sunlight, particularly during the warm summer months, and the increased availability of nutrients, such as phosphates and nitrates, will provide ideal conditions for the formation of blooms. These blooms can vary widely in colour.

They produce three different types of toxin: hepatoxin (damages the liver); neurotoxins (damages the nervous system); or those that cause allergic reactions.

Water that flows slowly with low turbulence – such as regulated rivers, dams or water storages – is at a higher risk of algal blooms.

Do not swim, wade, fish or drink from water courses that have blue green algal blooms and do not let dogs and other animals wade or swim in affected water.

Council’s Environmental Health Unit works closely with other Council departments to monitor and treat water courses on Council land and public spaces.

If you are concerned about a water course with blue green algal bloom, contact the Environmental Health unit on 9262 6197.

External Links

Department of Health
Department of Primary Industries 
Water Quality Research Australia. Blue Green Algae: A Guide