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Goldfish (Carassius auratus)

Introduced goldfish are established in Australian waters, including ponds and reservoirs. Dense populations can damage aquatic vegetation and increase water turbidity, and goldfish have been reported feeding on the eggs and larvae of native species in Australia.

Key facts

Type: Pest animal, fish.

Native to: China, Korea and Eurasia, from the Lena to the Amur Rivers.

Established in: QLD, NSW, ACT, VIC, TAS, SA, WA.

Other names: Carassin, Wild goldfish.

Best time to act: Survey and undertake approved removal in warmer months, when goldfish may be active and spawning over aquatic vegetation.

Identification

  • A freshwater fish with a stout, robust body, an elevated back and a short head.
  • The mouth is set underneath the head and has no barbels.
  • Wild fish are usually grey-green above, brassy on the sides, and white or yellow underneath; ornamental fish may have very different colours.
  • The dorsal fin is long and has a stout, saw-toothed spine-like ray.
  • Adults are commonly 120 to 170 mm long, but can reach about 410 mm.
  • Look-alike: Young common carp can resemble goldfish, but common carp have two barbels and can grow much larger.
  • Look-alike: Other Carassius species and their hybrids can be difficult to distinguish from goldfish, especially when young.

Where it lives

In Australia, goldfish live in freshwater ponds and reservoirs and favour still or slow-moving, vegetated water, including urban waterways.

Why it matters

  • High-density populations can destroy aquatic plants and increase turbidity.
  • In Australia, goldfish have been reported feeding on eggs and larvae of native species.
  • Goldfish can carry the ectoparasites Lernaea cyprinacea and Argulus japonicus; the effects of these parasites on wild fish populations are unknown.

How it spreads

  • Goldfish spread through deliberate or accidental release, including releases of pet fish.
  • They are also sold as bait and feeder fish, creating opportunities for accidental release or movement between waters.
  • Do not move live fish or water between waterways, ponds or dams.

Control methods

  • Seek advice from the relevant state or territory fisheries or biosecurity agency before starting control, and use only approved methods.
  • Where authorised, physical removal using suitable nets or traps may be used; any drawdown or other water-level intervention should be planned to minimise harm to native fish and other wildlife.
  • Do not release captured goldfish into another waterway or keep them alive for later use as bait.
  • Check treated sites again and repeat approved control as needed; report new or suspect populations to the relevant state or territory agency.

Site hygiene and welfare

  • Clean and dry boats, nets, traps, boots and other equipment before moving between waterbodies, and remove any attached plants, fish or debris.
  • Drain water from boats and gear at the site, and do not transfer water, fish or aquatic material to another waterbody.
  • Use methods set out in the national model codes of practice and standard operating procedures for the species.
  • Coordinate control with neighbours and the local government biosecurity plan, as isolated effort is quickly undone by reinvasion.

Classification by state

  • Australia (national): No national listing. Managed under state and territory law.
  • Queensland: Not prohibited or restricted. Not listed as prohibited or restricted matter in Queensland. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: General biosecurity duty. Not prohibited matter in NSW. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: Not declared. Not declared under the Catchment and Land Protection Act 1994. Other Victorian laws may still apply.
  • South Australia: Not declared. Not declared under the Landscape South Australia Act 2019. Other laws may still apply.
  • Western Australia: Not listed. Not found in the Western Australian Organism List. Check with DPIRD before moving or keeping it.
  • Tasmania: Not a declared pest. Not a declared pest or prohibited matter in Tasmania. Importing animals is still controlled by Biosecurity Tasmania.
  • Northern Territory: Not a declared pest. Not on an NT declared or prohibited list. Check with the NT Government before keeping, moving or releasing it.
  • Australian Capital Territory: Not declared. Not declared under the Biosecurity Act 2023 (ACT). A general biosecurity duty still applies.

Legal obligations

Every state and territory places a duty on landholders and people working on land to prevent the spread of invasive species, such as the general biosecurity obligation in Queensland and the general biosecurity duty in New South Wales. Declarations and control requirements differ between states and local government areas, so check the current official list before work starts.

  • Queensland: Biosecurity Act 2014 (Qld), administered by Biosecurity Queensland (13 25 23)
  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development
  • Australian Capital Territory: Biosecurity Act 2023 (ACT), administered by ACT Biosecurity
  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria
  • Tasmania: Biosecurity Act 2019 (Tas), administered by Biosecurity Tasmania
  • South Australia: Landscape South Australia Act 2019 (SA), administered by the regional landscape board
  • Western Australia: Biosecurity and Agriculture Management Act 2007 (WA), administered by the WA Department of Primary Industries and Regional Development

Sources