Azolla growth on wetlands

21 November 2019

Residents may have recently noticed a water fern covering the surface of many of our wetlands.

Azolla, is a native water fern which appears seasonally during the warmer months in slow moving water and is currently covering the surface of many of Greater Dandenong's wetlands. It is a naturally occurring native fern that is beneficial to the fauna and wetlands in our city.

At this time of the year Azolla can cover the surface of our waterways, but is only temporary and for a short time. Azolla is not harmful to Greater Dandenong residents. In fact, Azolla can prevent blue-green algae blooms by taking up excess nutrients in the water, and also provides food for birds and insects.

Azolla spreads through spores or plant fragments transported by water, animals, boats, vehicles and human activities. It is typically found in waterways that have high nutrient levels and water temperatures.

When conditions are right, the plant can be fast spreading, forming carpets that cover the surface of the water.

Read Azolla information sheet

For any further question, please contact Council's Parks Unit on 8571 1702.