Tackling the green invaders
One of the regular challenges the Georges River faces is the invasion of aquatic weeds. These intruders, such as Frogbit (Limnobium laevigatum), Alligator weed (Alternanthera philoxeroides), and Ludwigia (Ludwigia peruviana), pose a significant threat to the river’s ecosystem. Their rapid spread and aggressive nature have disrupted local habitats, reduced food and shelter for aquatic animals, and even affected human recreational activities along the river.
Recent weed inspection by Georges Riverkeeper
In collaboration with Liverpool City Council, Georges Riverkeeper recently conducted a targeted weed inspection above the Liverpool Weir. This inspection focused on locating and assessing the presence of Frogbit, Ludwigia, and Alligator weed. Fortunately, the results have been promising. Ongoing efforts by the council to control and eradicate these troublesome species have proven effective.
A combination of mechanical removal and herbicide treatments has been employed in the past to tackle the weeds. Mechanical methods involve the use of booms to physically remove weed mats from the water’s surface, while carefully regulated herbicide treatments help ensure the complete removal of root systems. These efforts not only reduce the spread of invasive weeds but also promote the growth and diversity of native plants, contributing to the overall health of the Georges River ecosystem.
The impact of invasive weeds
Aquatic weeds are notorious for their ability to outcompete native species, which has a domino effect on local ecosystems.
Frogbit, a floating weed with small leaves, forms dense mats that block sunlight, inhibiting photosynthesis and creating low-oxygen conditions unsuitable for aquatic life.
Ludwigia, another persistent invader, exacerbates the issue by altering water flow and contributing to sediment build-up, potentially increasing the risk of flooding.
Alligator weed, perhaps the most notorious of the bunch, not only forms dense mats that choke waterways but also affects primary production. It has been known to destroy crops and turf farming, costing millions annually in NSW. Additionally, Alligator weed poses a threat to livestock, particularly light-pigmented cattle, by causing photosensitisation, which can lead to cancerous lesions.
How you can help. Simple actions can make a big difference!
While local councils and Georges Riverkeeper are taking significant steps to protect the river, the community can also play a crucial role in preventing further weed infestations. Here are some simple actions you can take to make a big difference:
Clean Your Gear: If you enjoy fishing or boating, always clean your equipment and boats to prevent the spread of weed fragments.
Choose Native Plants: Avoid planting non-native species in your garden or aquarium. Opt for native plants, which are less likely to become invasive. Purchasing prohibited species like Frogbit is illegal in NSW and can lead to heavy fines.
Report Sightings: If you spot any of these invasive weeds, quick action is vital. Report sightings to the NSW Biodiversity Helpline on 1800 680 244 to help prevent their spread.
