Blue Green Algae

Cyanobacteria (blue-green algae) are a common seasonal occurrence in Victoria and NSW and a natural component of most aquatic systems, including rivers, 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.

More information (including warnings and public alerts):