Cabomba

Native to North and South America, cabomba is a fully submerged aquatic plant, originally introduced to Australia as an aquarium plant. While 5 species of cabomba are recognised, only 1 of these, Cabomba caroliniana, is known to be naturalised in Australia.

Cabomba is an aggressive perennial that can form dense canopies below the water surface. Infestations displace native plants and animals, affect water quality, and impede recreational water users.

Cabomba caroliniana is a restricted invasive plant under the Biosecurity Act 2014.

Scientific name

Cabomba caroliniana

Other names

Fanwort

Description

  • Perennial, submerged aquatic plant with multiple stems up to 10m long.
  • Submerged leaves and stems have thin gelatinous coating.
  • Leaves are opposite and repeatedly divided to form feathery, fan-shaped structures.
  • Flowers are white, produced above surface, preceded by few narrow floating leaves.
  • Plants can form dense canopies below water surface.

Habitat

  • Grows in ponds, lakes and quiet streams.
  • Generally rooted in water 1-3m deep (sometimes up to 6m) but continues to grow free-floating if uprooted.
  • Thrives in cool and warm waters.
  • Grows in shade and full sun.

Distribution in Queensland

  • Occurs in Queensland's Wet Tropics, particularly Leslie Dam on Atherton Tableland.
  • Also widespread in South East Queensland, with large infestations in Ewen Maddock Dam near Caloundra and Lake Macdonald near Noosa.

Life cycle

  • Grows and flowers predominantly in summer.
  • Spreads from stem fragments (regeneration by seeds has so far only been observed in Northern Territory and Victoria).

Affected animals

humans; native aquatic animals

Impacts

Environmental

  • Aggressively invades native freshwater systems.
  • Transforms aquatic ecosystems.
  • Displaces native plants.
  • Affects native wildlife.

Economic

  • Affects water quality.
  • Increases siltation in lakes.
  • Obstructs creeks, lakes and dams.
  • Interferes with infrastructure (e.g. irrigation).

Social

  • Impedes aquatic recreational activities.
  • Endangers swimmers who can become entangled.

How it is spread

  • Fragments spread by water flow, floods, watercraft, trailers, fishing gear and animals.
  • Spread mainly by humans.

Control

Mechanical control

  • Hand-pull small infestations, taking care to remove entire plant to prevent re-infestation.
  • Use harvesters on larger areas for  temporary control.

Herbicide control

  • Carfentrazone is currently the only herbicide registered for control of cabomba.

See the Cabomba fact sheet (PDF, 1.1MB) for herbicide control and application rates.

Biological control

  • No known biological control agents.

Legal requirements

  • Cabomba caroliniana is a restricted invasive plant under the Biosecurity Act 2014.
  • It must not be given away, sold, or released into the environment without a permit.
  • All other Cabomba species are prohibited invasive plants.
  • All sightings of other Cabomba species must be reported to Biosecurity Queensland within 24 hours of the sighting.
  • The Act requires everyone to take all reasonable and practical steps to minimise the risks associated with invasive plants and animals under their control. This is called a general biosecurity obligation (GBO).
  • At a local level, each local government must have a biosecurity plan that covers invasive plants and animals in its area. This plan may include actions to be taken on certain species. Some of these actions may be required under local laws. Contact your local government for more information.

More information