Aquatic weeds

Aquatic weeds in NSW are a real problem and have been introduced through various ways. Weeds are unwanted and can cause various types of damage.

Aquatic weeds have been introduced into the water ways because people used them for nursery and plant display in backyard pools and aquariums. Other activities which have helped spread weeds include boating or fishing. The boat propellers can cut into the weed and since the plant has become smaller, it is now easier for it to travel further.

Which weeds are pest?

Spieces such as hyacinth, cabomba, alligator weed, Arrowhead, East Indian hygrophila are some of the common weeds considered pest in NSW. The NSW Department of Primary Industries have prodived are full list of water weeds here.

What damages can aquatic weeds cause?

Water weeds can be problemtic and some of the problems they create include:

  • Reduce the oxygen levels of the water. Potentially can be a problem for other plants and life forms in the water.
  • Reduce the water quality
  • Fishing activities and boating activities can find it difficult to move around
  • Hazardous for other animals and swimmers. Can cause drowning.

As part of a 2014 project investigating potential aquatic weed risks and spread pathways in the Murray-Darling Basin (MDB), distribution maps were prepared for five high-priority aquatic weeds; sagittaria, water hyacinth, alligator weed, cabomba and Mexican water lily. These weeds have high potential to spread from their current infestations in the MDB. Maps were developed for each of the Natural Resource Management (NRM) regions that border the Murray River, and that contain any of the weeds listed above. Please note that the data is current as of date printed on individual maps, and that they may contain inaccurate or incomplete data, as not all points have been verified.

Learn more about water weeds:

Alligator weeds: This acquatic plant is a real pest. Potentially devastating to the surrounding environment. It is known to affect both water and on land. It is considered one of the most worst weeds in the world. Read more on Alligator weed.


Arrow head plant (Aquatic weed)

Arrowhead (Sagittaria): Found in New South Wales, Arrowhead aquatic weed is known to block waterways, block irrigation channels, choke watercourses and interfere with water flow. The plant is known to easily spread, it can have hundreds or thousands of seeds to help it spread. Read more on Arrowhead.


East Indian hygrophila

East Indian hygrophila: is a plant which can easily spread and become a real problem to waterways. The aquatic plant can spread whenever the stems are broken and transported by the boats or flowing water. East Indian hygrophila are found in tropical places, it is in South East Asia, United States and also South Eastern Queensland and New South Wales. Read more on East Indian hygrophila.


Hygrophila | Aquatic weeds

Hygrophila: The hygrophila plant can cause a lot of damage to the natural environment. It is known to dominate out other plants and interfer with boating and fishing activities. Hygrophila are known to easily spready quickly and grows up to 1.5 m. Read more on Hygrophila.


sagittaria platyphylla
Sagittaria Platyphylla

Sagittaria Platyphylla: is a plant that easily grows and rapidly spreads. The sagittaria platyphylla can grow hundreds of seeds, which can be spread through the waterways or through animals. The plant is problematic, it is known to choke waterways, reduce the water quality and impact water activities. Read more on sagittaria platyphylla.