The ORC’s Environmental Data Portal is experiencing high traffic volumes affecting its effectiveness at present. The site is being worked on at present and people are asked to be patient. Please be considerate in using this tool, some people require access to the EDP for important decision-making today.
Environmental Data PortalThe ORC’s Environmental Data Portal is experiencing high traffic volumes affecting its effectiveness at present. The site is being worked on at present and people are asked to be patient. Please be considerate in using this tool, some people require access to the EDP for important decision-making today.
Common name: | Freshwater gold clam, Asian gold clam |
Scientific name: | Corbicula fluminea/Corbicula australis |
Management programme: | Unwanted organism |
If you have seen or suspect the presence of this pest you must report the sighting.
Report the sighting to Biosecurity New Zealand at 0800 80 99 66.
This freshwater mollusc (also known as Asian gold clam) was discovered along a stretch of the Waikato River in May 2023. Biosecurity New Zealand is working with iwi and other partners to decide future actions.
Keep reading to find out more about the clam and how you can help to prevent it from infesting Otago’s waterways.
These freshwater molluscs (also known as freshwater gold clam) reproduce rapidly and form large populations that can clog water-based infrastructure such as electric generation plants, irrigation systems, and water treatment plants. Corbicula has been implicated with billions of dollars of economic damage overseas. They are filter feeders that have the potential to affect biodiversity and compete with native species for food.
Otago’s waterways are modelled to be suitable for clam establishment.
The two species of Corbicula, C.australis and C.fluminea are native to Australia and Eastern Asia respectively, with the latterwidely established in North and South America and Europe.Overseas, this clam has proved difficult to control and eradication has never been achieved.
Freshwater gold clams were first found in the Bob’s Landing area of the Waikato River near Lake Karāpiro in early May 2023, and identified as Corbicula fluminea. Since then, Corbicula fluminea has been confirmed in the Waikato River from Lake Maraetai Landing to Tuakau. Corbicula australis has been found in a small, contained water park near Taupō. Biosecurity New Zealand is working with iwi and other partners to decide future actions.
Keep reading to find out more about the clam and how you can help to prevent it from infesting Otago’s waterways.
Why not? Freshwater gold clam are small filter-feeding shellfish that eat deposits from the river or lake bed and accumulate toxins in their gut. Because of this, they are not safe for human consumption.
You must notify the Otago Regional Council or the Ministry for Primary Industries if you suspect the presence of this organism
If you think you've seen the freshwater gold clam:
If you are using the online reporting form, you'll need to start by saying you are a member of the public, that you want to make a report about 'a marine or freshwater issue' and then select 'freshwater fish or crustacean' from the dropdown box that will appear.
Then you will be taken through some further questions including contact information and asked to load your images.
If you fish, swim, boat or row, follow the Check, Clean, Dry guidelines to help stop the spread of this clam to other rivers and lakes through New Zealand. Before moving to another location at the river, or to another river or lake:
Note: The 'Check, Clean, Dry' advice may be adjusted as further technical information becomes available. Refer to the manufacturer’s instructions for gear and any commercial treatments.
Freshwater gold clam (Corbicula fluminea) – Fact Sheet
Biosecurity New Zealand has been working in partnership with iwi, councils and other key stakeholders to protect the water we love by preventing the spread of freshwater clams.
An unwanted organism is not managed under the ORC Pest Plan but may be controlled as part of our Biosecurity Strategy.
CHECK your gear for stowaways and remove the pests either at the site or put it in the rubbish bin. CLEAN your gear thoroughly (one way is to use 10% dishwashing detergent mixed with water and leave the item wet for 10 minutes, visit this page for more ways). DRY it for 48 hours before relocating to another waterway!