Azolla

Azolla weed
Azolla in local water way

Azolla is a small native free floating fern that is found in many waterways in the Campbelltown local government area.

Azolla grows from 1cm to 2.5cm wide and is a bright green colour with its colour changing to deep red when it is exposed to the sun. Azolla grows in waterways in dense patches, which can look like a green or red carpet and from a distance it may be confused with Salvinia, a noxious aquatic weed, or the scum of a bluegreen algal bloom.

Although Azolla can appear intrusive it can be highly beneficial to the aquatic environment in many ways, including:

  • improving water quality by capturing excess nutrients from the water
  • providing a food source and habitat for a variety of aquatic animals
  • discouraging algal blooms by reducing the penetration of sunlight into the water.

How does Council manage Azolla?

Because Azolla is a native species with numerous benefits for aquatic ecosystems, Council does not automatically remove it in response to aesthetic concerns. In warmer months when sunlight is plentiful, Azolla is likely to be more prolific. The removal of Azolla can actually have negative impacts on a waterway. If the Azolla is no longer there to take up nutrients from the water column, they become available for blue-green algae, which can bloom in nutrient rich environments.

Azolla growing at Park Central
Azolla growing at Park Central

How can the community reduce the impact of nutrients on waterways?

By following a few, simple steps you too can help to ensure our local waterways remain healthy.

  • Pick up animal droppings from lawns and parks and place them in a bin
  • Do not feed native wildlife. Providing human food for native animals can attract pest species to the system and increase faecal waste, which affects water quality. Animals can also become reliant on human feeding and lose their natural ability to forage
  • Disposing of garden waste in or near a water body can allow weeds to enter a system and add excessive nutrient
  • Always place garden waste in a bin or take it to the tip
  • Never wash cars or household equipment in the driveway or the street. This will help to prevent detergents entering the stormwater system
  • Use fertilisers in moderation and strictly according to directions on the product label
  • When undertaking building or home renovations, keep building materials covered and install silt fencing along property boundaries where appropriate.

Everyone has a responsibility to reduce water pollution. By following these few simple steps you too can help ensure our local waterways remain healthy.

For further information contact Council's Natural Areas Team on 02 4645 4601 or by email to open.space@campbelltown.nsw.gov.au