Cyanobacteria (blue-green algae) are a common seasonal occurrence in Victoria and a natural component of most aquatic systems, including streams, lakes, estuaries and the sea.
Individual cells are very small and are normally not visible in a water body.
But numbers can increase rapidly and blooms, or scums, become easily visible across the water surface.
Blooms can be triggered by nutrient levels, low inflows, lower storage volumes and warmer weather conditions.
Blooms can be unsightly, ranging in colour from dark-green to yellowish-brown. They develop a paint-like consistency as they dry out and often have a pungent smell.
Large numbers of blue-green algae in water bodies can produce toxins that can affect the health of humans, animals, birds and livestock as well as harm the environment.
In Victoria, blue-green algae is monitored regularly by water corporations and local waterway managers through sampling and testing.
An algae outbreak is managed based on the use of the water body and the density and nature of the bloom.
Farm dams are quite susceptible to algal blooms. Further, they are difficult to reclaim once a bloom has occurred.
It is better to prevent the build-up of predisposing conditions rather than trying to reclaim a contaminated dam.
More information is available on the Agriculture Victoria website:
For the latest information on blue-green algae events you should contact the manager responsible for the water body, such as the local council, water corporation or the Department of Environment, Land, Water and Planning.
Further information can be found on the following websites:
- Department of Economic Development, Jobs, Transport and Resources
- Department of Health and Human Services
- Water Quality Research Australia
The Blue-green Algae Circular informs local water managers about algal bloom coordination within Victoria.
The circular has a bio-volume calculator to determine the level of cell count at which a response may be required. The circular also has a blue-green algae notification form.
- Blue Green Algae Circular (DOCX, 2.3 MB)
- Biovolume Calculator (Excel, 56.8 KB)
- Blue-Green Algae Notification Form (Excel, 196.5 KB)
- Sample BGA Regional Coordination Plan (DOC, 172.5 KB)
- Sample BGA Risk Management Plan (PDF, 116.9 KB) or Word version (DOCX, 216.1 KB)
The following documents can be accessed via the Water Research Australia website:
- Blue-green algae: a guide – Fact sheet by the Cooperative Research Centre (CRC) for Water Quality and Treatment on blue-green algae
- Management strategies for Cyanobacteria (blue-green algae): a guide for water utilities – This guide for water utilities consolidates knowledge on managing blue-green algae. It covers the management of source water, the treatment process, an outline to health effects of blue-green algae and current guidelines and standards.
- Cyanobacteria: management and implications for water quality – Series of technical fact sheets about CRC research and management implications for the water industry.
- Second National Cyanobacterial Workshop – Abstracts and some presentations from the Second National Cyanobacterial Workshop held in Melbourne in 2010.
The following document can be found on the NHMRC website:
- Guidelines for managing risks in recreational water– National Health and Medical Research Council guidelines to help manage recreational water bodies.
Algae are a naturally occurring organism present in all waterways. The Gippsland Lakes contain many different types of algae at varying levels as part of the natural environment and balance of the Lakes system.
Weather conditions, nutrient levels, salinity and water flows all affect the levels of algae and can contribute to the formation of algal blooms on the Lakes.
Warmer weather conditions are likely to lead to a natural increase in the abundance and variety of algae and other organisms in the Lakes.
If an algal bloom develops on the Gippsland Lakes, information (factsheets and maps) will be available on this website and through local outlets, including local media and Visitor Information Centres and circulated to tourism operators. It will also be posted on the DELWP Gippsland Facebook page.
DELWP will resume weekly monitoring and reporting in the summer months unless there are any significant changes to algae levels. Monthly testing will continue until then.
Gippsland Lakes Update – 7 July 2021
The Department of Environment, Land, Water and Planning (DELWP), in consultation with the Department of Health (DH) advises people not to eat shellfish, including mussels and other types of shellfish collected from anywhere in the Gippsland Lakes
There are high levels of the algae Prorocentrum cordatum present in Lake Victoria and Lake King. Therefore it is recommended not to consume shellfish such as mussels harvested from anywhere in the lakes system Poor water quality may be present in some locations, and reiterate the general message not to swim in locations with murky or green water.
Page last updated: 15/07/21