A NSW Government website

Freshwater gold clam


Freshwater gold clam on gravelly substrateThe freshwater gold clam (Corbicula fluminea) is a pest that can harm Australia’s rivers and lakes. It grows and spreads quickly, sending tiny baby clams (larvae) far through flowing water.

This clam can block pipes and water systems, harm native species, and disrupt natural ecosystems. Once it’s in a river or lake, it’s nearly impossible to remove.

The freshwater gold clam was first found in the Brisbane River in 2023. It has now spread through more than 70 km of the river. The Queensland government are keeping a close watch to understand how far it’s gone and how to manage it.

National guidelines have been created to help us work together to stop this pest. You can read them here: National guidelines for the management of Corbicula fluminea

Reporting

If you think you have seen a freshwater gold clam in NSW, please take several clear, high-resolution photos of the clam. For identification, we need to see the:

  1. Clam size – please include something for reference (e.g. a coin)
  2. Shell shape and markings – in particular the ridges on the shell
  3. Shell colour

Please report via the 24 hour EAD Hotline and send photos to aquatic.biosecurity@dpird.nsw.gov.au, along with details of when and where the clam was seen.

Identification

Key features

  • Has a thick yellowish-brown to black shell
  • Grows up to 65 mm, but usually smaller (<25 mm)
  • Juvenile shells oval-shaped, while adults become more triangular
  • Distinct widely spaced ridges (7–14 per cm)
  • Often found in dense clusters on sandy or gravelly riverbeds
  • Shell interior may be purple

Known locations

  • Recently detected for the first time in Australia in Brisbane River, Qld

Habitat

  • Found in freshwater rivers, lakes, and dams
  • Prefers sandy or gravelly substrates
  • Often near water intakes, plants, or man-made structures

Vectors

  • Illegal deliberate release
  • Contaminated boats and fishing equipment
  • Ballast and bilge water
  • Use as live bait

Impacts

  • Clogs pipes and water systems
  • Outcompetes native clams
  • Alters water quality and ecosystems
  • Costs millions in infrastructure damage overseas

Similar native species

These native species may be confused with the freshwater gold clam. These species do not need to be reported.

Australian corbicula / Little mussel (Corbicula australis)Open shells of Australian corbicula or little mussel (Corbicula australis) showing the finer ridges closer together running parallel to the mouth

Key features

  • Has a thinner, more oval shell
  • Features finer ridges (25–32 per cm)
  • Rarely exceeds 33 mm in size

Known locations

  • NT, Qld, Vic, NSW,  SA

Habitat

  • Inland rivers and steams
  • Often found in large numbers, living in sand, in shallow, flowing rivers

More information

Freshwater gold clam (Corbicula fluminea) alert