The introduction of exotic aquatic plants into Australia and particularly NSW has affected our wetlands, streams, rivers and estuaries.

Invasive aquatic weeds include:

• Alligator Weed (Alternanthera philoxeroides)
• Salvinia (Salvinia molesta),
• Water Hyacinth (Eichhornia crassipes)
• Water Lettuce (Pistia stratiotes)

These weeds were introduced into the waterways and have:

• Reduced fish populations
• Choked water systems
• Depleted food sources and breeding areas for wildlife
• Provided shelter for mosquito populations.

Alligator Weed

Alligator Weed has infested waterways in Newcastle. It is particularly problematic as it not only grows in water but also invades adjoining land.

Alligator Weed is easily spread and once established it is virtually impossible to eradicate. Some of these aquatic weeds can double their mass in 5 – 10 days. They excel in waterways with high nutrient levels.

Prevention

Preventing the introduction of noxious aquatic weeds into local waterways is difficult.

A major problem stems from the use of these plants in aquariums and backyard ponds. The weeds are spread when they are transferred from aquariums and ponds into waterways. Fines may be issued for this and other activities which do no comply with the control requirements of the Noxious Weeds Act.

Control options

Land owners and occupiers should contact Council’s Noxious Weeds Officers on 02 4974 6000 for advice on suitable control options for specific locations.

Herbicide application in and around water is a reasonable control method, but these applications are strictly controlled by government regulations. Incorrect use of herbicides can cause damage locally and have an impact downstream and on attached ecosystems.

We need your help to control weeds. Report any infestations you find in open waterways or in / on business premises and private properties.

Please help to stop these noxious plants taking over our waterways and river systems.

For further information on aquatic weeds

Contact Council's Noxious Weeds Officers on 02 4974 6000.

NSW Department of Primary Industries