Aquatic Weeds

Many of Queensland and New South Wales’ freshwater lakes, billabongs, creeks and rivers are threatened by the introduction of non-native aquatic plants.

Since European settlement aquatic plants have been introduced for many purposes. Some species have been purposefully introduced as ponded pasture species (plants introduced to areas of artificially impounded water), to be additional fodder for grazing or harvesting, while others have been accidentally introduced (occasionally on purpose) as aquarium plants, ornamental pond and lagoon species.

Invasive weeds have the potential to destroy native habitats by outcompeting aquatic ecosystems, restricting water flow, depleting oxygen in water bodies, and degrading the waterways to the point that fish kills may result.

Aquatic weeds can spread easily, for example; weeds can be carried downstream or spread by birds and humans in the form of seeds or as a broken or torn weed. Parts of weeds that have broken off often regrow in a new location.  The following is a list of declared aquatic weed species commonly found on the Gold Coast:

• Alligator Weed – Alternanthera philoxeroides
• Cabomba – Cabomba caroliniana
• Salvinia – Salvinia molesta
• Senegal Tea Plant – Gymnocoronis spilanthoides
• Water Hyacinth – Eichornia crassipes
• Water Lettuce – Pristia stratiotes

Residents can help to stop the spread of these aquatic weeds by disposing of unwanted aquatic plants thoughtfully, keeping weeds under control and working towards getting rid of them completely. Please see below for a brief description of these weeds with an accompanying photo.

Alligator Weed

Alternanthera philoxeroides
State declaration – Class 1 Declared Pest
Council dec. – Class E Early detection and eradication.
Alligator weed restricts water flow in creeks, channels and drains and reduces water quality.
It forms new shoots in Spring from nodes on existing stems. Regrowth occurs quickly from stems or underground rhizomes.

• Cabomba
• Salvinia
• Senegal tea plant
• Water hyacinth
• Water Lettuce

You can find more information about these weeds <a href=”http://www.goldcoast.qld.gov.au/environment/pests-weeds-546.html”>HERE (City of Gold Coast website).</a>