Freshwater gold clam

Common name: Freshwater gold clam

Alternative names: Golden clam, Freshwater invasive clam, Asian gold clam

Botanical name: Corbicula fluminea

Management programme: This clam is classified as an Unwanted Organism under the Biosecurity Act. It was discovered in New Zealand for the first time in May 2023 when it was found in the Waikato River. The incursion response is being led by Biosecurity New Zealand (a business unit of the Ministry of Primary Industries).

Gold clam is not a listed species within the Bay of Plenty Regional Pest Management Plan (RPMP) 2020–2030. Under rule 7 of the Bay of Plenty Regional Pest Management Plan (RPMP) 2020–2030 provision is made for stopping the spread of freshwater pests by requiring all boat ramp users to certify that their vessel, craft, and trailer are free from freshwater pest fish and pest plants.

The Biosecurity New Zealand website has details of the new Check Clean Dry requirements developed for this clam, as well as other invasives, which must be used in the North Island.

A key difference is a requirement to soak absorbent gear like lifejackets in hot tapwater – 55degC – for at least 5 minutes to kill sticky juvenile clams, which can be too small to see.

About Freshwater gold clam (Corbicula fluminea)

  • The freshwater gold clam is native to eastern Asia and is widely established in North and South America and Europe.

  • These clams reproduce rapidly and form large populations that can clog water-based infrastructure such as electricity generation plants, irrigation systems, and water treatment plants. They are filter feeders that can potentially compete with native species for food. We do not yet know how this species will respond in New Zealand conditions.
  • Overseas, this clam has proved difficult to control and eradication has never been achieved.

You can read more information about gold clam on the Biosecurity New Zealand website 

To report suspected gold clam please call Biosecurity New Zealand on 0800 800 99 66 or complete the online reporting form at

Find out how to identify freshwater gold clams 

Check this page for updates

30th November 2023

A new Controlled Area Notice (CAN) for the Waikato River was put in place at 11:59pm on Thursday 23 November. Under this CAN, which covers the 225km stretch of river from the Whakamaru Dam to the river mouth:
a) recreational watercraft (other than wake boats) and equipment on the affected part of the Waikato River are required to undertake the clam specific Check, Clean, Dry procedures; and
b) wake boats are prevented from moving from the affected part of the Waikato River to any other freshwater environment.

70 signs informing Waikato River users of the new CAN were installed at boat ramps along the Waikato River and Lake Taupō during the weekend of 24-26 November.

Biosecurity New Zealand staff have been working with regional councils across the country to implement long term surveillance of major water bodies popular for boating and fishing in their regions. To date, nine councils have received eDNA sampling kits and two will begin sampling in December.

Te Arawa Lakes Trust (on behalf of the Bay of Plenty Regional Council) has completed eDNA sampling in six of the 14 Te Arawa Lakes in the Bay of Plenty. Sampling in the remaining lakes continues. This sampling was requested by Ngati Tarāwhai as part of their efforts to prevent the establishment of freshwater gold clams in Lake Ōkataina.

For more information on the Freshwater gold clam response visit this Biosecurity New Zealand page.

10th November 2023

New protections for Te Arawa lakes are in place via a mechanism under the Biosecurity Act called a Controlled Area Notice (CAN). The new CAN will take effect from midday Friday 10 November 2023.

Full details of the CAN are available here.

For Lake Ōkataina

  • At midday on Friday 10 November 2023, the temporary CAN that closed Lake Ōkataina on 1 October will be lifted and replaced by a new CAN applying to all 14 Te Arawa lakes with special requirements for Lake Ōkataina.
  • Under the special requirements of the new CAN, all boats must be cleaned at a designated wash station in Rotorua before entering Lake Ōkataina. This is in addition to the clam-specific Check Clean Dry requirements for all boats that have been in the Waikato River.
  • Access to Lake Ōkataina will be controlled. The lake will be open Friday to Sunday 6:30am-7:00pm. 

For all 14 Te Arawa lakes

  • Any boat that has been in the Waikato River in the previous 30 days must be cleaned at a designated wash station before entering the water. This is in addition to the new Check Clean Dry requirements for all boats that have been in the Waikato River.

Designated wash station

  • Lake users must use a designated wash station for the washdown. This is The Wash Place, located in Rotorua at 338 Te Ngae Road.
  • At the station, boaties will need to:
  • Wash down their watercraft and trailer and drain any remaining water.
  • Scan the QR code or visit the webpage shown and complete the online form to prove they’ve completed the washdown.
  • The Wash Place is a commercial facility and there will be a cost for washing your boat and trailer depending on the length of the cycle chosen. Payment facilities are availabe for debit and credit cards, and coins.
  • The station will be open 24/7 and detailed instructions about how to complete the wash are provided at the site. It will be temporarily staffed to assist people with fulfilling the washdown requirements.
  • Biosecurity New Zealand is working through options for additional wash stations in the Bay of Plenty.

31st October 2023

  • Temporary biosecurity rules for Lake Ōkataina have been extended by Biosecurity New Zealand. The lake has been closed to boating and fishing since October 2023 through a mechanism called a Controlled Area Notice (CAN) under the Biosecurity Act, and will remain closed for up to 2 further weeks (mid-November) to allow time to work through required approvals and works for a wash station to be installed on Lake Ōkataina Rd. That facility will provide assurance that boats entering the lake are free of freshwater gold clams.
  • Other sites to install wash stations for boats and trailers entering the Rotorua area are being investigated.
  • People travelling from Waikato to Te Arawa lakes, including Ōkataina, will need to meet Check Clean Dry requirements for freshwater gold clam before going in the water.
  • Biosecurity New Zealand have launched a paid campaign covering the North Island – starting in the Waikato – on radio, billboards and posters – to raise awareness around gold clam.
  • A permanent wash station is installed and operational at the Mighty River Domain on the shore of Lake Karāpiro by the main boat ramp, mainly used by power boats and jetskiers. The station has a pressure sprayer so boaties blast their craft with water, removing young clams with mucous strands. Biosecurity New Zealand have been exploring options for further wash stations in Waikato.

10th October 2023

  • For the foreseeable future Te Arawa Lakes Trust (TALT) are declining applications for lakes-based events (including lake usages, full or partial closures) due to the threat of freshwater gold clams.
  • The boat and trailer self-certification process can now be completed directly online at the boat ramp. New signage which includes boat ramp specific QR codes has been installed this week and removes the obstacles previously encountered when relying on hard copy forms being available.
  • Boat ramp compliance checks for the summer period have commenced and will run every weekend throughout the summer and every day over the peak summer / Christmas break.

2nd October 2023

  • Biosecurity New Zealand issued a Controlled Area Notice (CAN) for Lake Ōkataina for a period of one month from 1 – 31st October as a preventative measure against a gold clam incursion and to allow time to install a boat washdown station.
  • The CAN prohibits the movement of boats and other watercraft and fishing equipment - including rods, waders and nets – into the lake. The lake can still be enjoyed for other activities such as walking on the shore, picnics and swimming.
  • People who have a need to continue using boats in the lake during the period can apply for a special permit by contacting Biosecurity New Zealand on
  • All other Rotorua Te Arawa boat ramps were open for the start of the trout fishing season on Sunday 1 October, excluding those already closed due to exceptionally high lake levels.

27 September 2023

  • There is no evidence of gold clam currently in Bay of Plenty region 
  • The Rotorua Te Arawa lakes, including Lake Ōkataina, are understood to be free of the clam, based on both comprehensive snorkel surveillance undertaken in June 2023 and checks of eDNA samples taken over the last three years.
  • At the Rotorua Te Arawa Lakes Strategy Group meeting held on Friday 22 September, a motion was passed to support in principle, Ngāti Tarāwhai iwi Trust’s request for urgent investigation into a temporary closure of Lake Ōkataina under the Biosecurity Act, by Biosecurity New Zealand, based on the significant biosecurity threat posed by freshwater gold clams. 
  • Ngāti Tarāwhai Iwi Trust have asked Biosecurity New Zealand to issue a Controlled Area Notice for Lake Ōkataina, as a preventative measure against a gold clam incursion
  • Working in partnership with Te Arawa Lakes Trust, Te Arawa Lakes Trust Biosecurity staff will be at the boat ramps on Trout Fishing Opening day (1 October) and throughout the summer to reinforce the compliance rules under rule 7 of the RPMP.

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